diff --git a/red/nodes/Flow.js b/red/nodes/Flow.js
index c54199142..857b6fa97 100644
--- a/red/nodes/Flow.js
+++ b/red/nodes/Flow.js
@@ -1,5 +1,5 @@
 /**
- * Copyright 2014 IBM Corp.
+ * Copyright 2015 IBM Corp.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -210,6 +210,7 @@ function Flow(config) {
     
     this.activeNodes = {};
     this.subflowInstanceNodes = {};
+    this.started = false;
 
     this.parseConfig(config);
     
@@ -251,7 +252,6 @@ Flow.prototype.parseConfig = function(config) {
         nodeType = nodeConfig.type;
         
         if (nodeConfig.credentials) {
-            credentials.extract(nodeConfig);
             delete nodeConfig.credentials;
         }
         
@@ -297,6 +297,7 @@ Flow.prototype.parseConfig = function(config) {
 }
 
 Flow.prototype.start = function() {
+    this.started = true;
     if (this.missingTypes.length > 0) {
         throw new Error("missing types");
     }
@@ -354,6 +355,7 @@ Flow.prototype.stop = function(nodeList) {
         }
         when.settle(promises).then(function() {
             events.emit("nodes-stopped");
+            flow.started = false;
             resolve();
         });
     });
@@ -368,7 +370,7 @@ Flow.prototype.typeRegistered = function(type) {
         var i = this.missingTypes.indexOf(type);
         if (i != -1) {
             this.missingTypes.splice(i,1);
-            if (this.missingTypes.length === 0) {
+            if (this.missingTypes.length === 0 && this.started) {
                 this.start();
             }
         }
@@ -505,7 +507,7 @@ Flow.prototype.diffFlow = function(config) {
     
     this.config.forEach(function(node) {
         for (var prop in node) {
-            if (node.hasOwnProperty(prop) && prop != "z") {
+            if (node.hasOwnProperty(prop) && prop != "z" && prop != "id" && prop != "wires") {
                 // This node has a property that references a changed node
                 // Assume it is a config node change and mark this node as
                 // changed.
@@ -553,7 +555,7 @@ Flow.prototype.diffFlow = function(config) {
         buildNodeLinks(newLinks,node,configNodes);
     });
     
-    var markLinkedNodes = function(linkChanged,changedNodes,linkMap,allNodes) {
+    var markLinkedNodes = function(linkChanged,otherChangedNodes,linkMap,allNodes) {
         var stack = Object.keys(changedNodes);
         var visited = {};
         
@@ -563,8 +565,8 @@ Flow.prototype.diffFlow = function(config) {
             var linkedNodes = linkMap[id];
             if (linkedNodes) {
                 for (var i=0;i<linkedNodes.length;i++) {
-                    linkedNodeId = linkedNodes[i];
-                    if (changedNodes[linkedNodeId] || linkChanged[linkedNodeId]) {
+                    var linkedNodeId = linkedNodes[i];
+                    if (changedNodes[linkedNodeId] || deletedNodes[linkedNodeId] || otherChangedNodes[linkedNodeId] || linkChanged[linkedNodeId]) {
                         // Do nothing - this linked node is already marked as changed, so will get done
                     } else {
                         linkChanged[linkedNodeId] = true;
@@ -575,12 +577,11 @@ Flow.prototype.diffFlow = function(config) {
         }
     }
     
-    markLinkedNodes(linkChangedNodes,changedNodes,newLinks,configNodes);
-    markLinkedNodes(linkChangedNodes,deletedNodes,activeLinks,flow.allNodes);
-    
+    markLinkedNodes(linkChangedNodes,{},newLinks,configNodes);
+    markLinkedNodes(linkChangedNodes,{},activeLinks,flow.allNodes);
     
     var modifiedLinkNodes = {};
-    
+
     config.forEach(function(node) {
         if (!changedNodes[node.id]) {
             // only concerned about unchanged nodes whose wiring may have changed
@@ -596,18 +597,21 @@ Flow.prototype.diffFlow = function(config) {
             newNodeLinks.forEach(function(link) {
                 if (newLinkMap[link] != oldLinkMap[link]) {
                     modifiedLinkNodes[node.id] = node;
-                    modifiedLinkNodes[link] = configNodes[link];
                     linkChangedNodes[node.id] = node;
-                    linkChangedNodes[link] = configNodes[link];
+                    if (!changedNodes[link] && !deletedNodes[link]) {
+                        modifiedLinkNodes[link] = configNodes[link];
+                        linkChangedNodes[link] = configNodes[link];
+                    }
                 }
             });
-            
             oldNodeLinks.forEach(function(link) {
                 if (newLinkMap[link] != oldLinkMap[link]) {
                     modifiedLinkNodes[node.id] = node;
-                    modifiedLinkNodes[link] = configNodes[link];
                     linkChangedNodes[node.id] = node;
-                    linkChangedNodes[link] = configNodes[link];
+                    if (!changedNodes[link] && !deletedNodes[link]) {
+                        modifiedLinkNodes[link] = configNodes[link];
+                        linkChangedNodes[link] = configNodes[link];
+                    }
                 }
             });
         }
@@ -615,7 +619,6 @@ Flow.prototype.diffFlow = function(config) {
     
     markLinkedNodes(linkChangedNodes,modifiedLinkNodes,newLinks,configNodes);
     
-    
     //config.forEach(function(n) {
     //    console.log((changedNodes[n.id]!=null)?"[C]":"[ ]",(linkChangedNodes[n.id]!=null)?"[L]":"[ ]","[ ]",n.id,n.type,n.name);
     //});
diff --git a/red/nodes/flows.js b/red/nodes/flows.js
index f4ad1d11b..db0164321 100644
--- a/red/nodes/flows.js
+++ b/red/nodes/flows.js
@@ -1,5 +1,5 @@
 /**
- * Copyright 2014 IBM Corp.
+ * Copyright 2014, 2015 IBM Corp.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
diff --git a/settings.js b/settings.js
index 0c15b80b1..ebf3dad6f 100644
--- a/settings.js
+++ b/settings.js
@@ -20,6 +20,18 @@
 
  
 module.exports = {
+    
+    adminAuth: {
+        type: "credentials",
+        users: [ {
+            username: "nol",
+            password: "5f4dcc3b5aa765d61d8327deb882cf99", // password
+            permissions: "*"
+        }],
+        anonymous: {
+            permissions: "read"
+        }
+    },
     // the tcp port that the Node-RED web server is listening on
     uiPort: 1880,
 
diff --git a/test/red/nodes/Flow_spec.js b/test/red/nodes/Flow_spec.js
index e69de29bb..8cb989282 100644
--- a/test/red/nodes/Flow_spec.js
+++ b/test/red/nodes/Flow_spec.js
@@ -0,0 +1,316 @@
+/**
+ * Copyright 2015 IBM Corp.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ **/
+ 
+
+var should = require("should");
+var sinon = require('sinon');
+var clone = require('clone');
+var Flow = require("../../../red/nodes/Flow");
+
+var typeRegistry = require("../../../red/nodes/registry");
+var credentials = require("../../../red/nodes/credentials");
+
+
+describe('Flow', function() {
+    describe('#constructor',function() {
+        it('called with an empty flow',function() {
+            var config = [];
+            var flow = new Flow(config);
+            config.should.eql(flow.getFlow());
+            
+            var nodeCount = 0;
+            flow.eachNode(function(node) {
+                nodeCount++;
+            });
+            
+            nodeCount.should.equal(0);
+        });
+        
+        it('called with a non-empty flow with no missing types', function() {
+            var getType = sinon.stub(typeRegistry,"get",function(type) {
+                // For this test, don't care what the actual type is, just
+                // that this returns a non-false result
+                return {};
+            });
+            try {
+                var config = [{id:"123",type:"test"}];
+                var flow = new Flow(config);
+                config.should.eql(flow.getFlow());
+                
+                flow.getMissingTypes().should.have.length(0);
+            } finally {
+                getType.restore();
+            }
+        });
+        
+        it('identifies missing types in a flow', function() {
+            var getType = sinon.stub(typeRegistry,"get",function(type) {
+                if (type == "test") {
+                    return {};
+                } else {
+                    return null;
+                }
+            });
+            try {
+                var config = [{id:"123",type:"test"},{id:"456",type:"test1"},{id:"789",type:"test2"}];
+                var flow = new Flow(config);
+                config.should.eql(flow.getFlow());
+                
+                flow.getMissingTypes().should.eql(["test1","test2"]);
+            } finally {
+                getType.restore();
+            }
+        });
+        
+        it('extracts node credentials', function() {
+            var getType = sinon.stub(typeRegistry,"get",function(type) {
+                // For this test, don't care what the actual type is, just
+                // that this returns a non-false result
+                return {};
+            });
+            
+            try {
+                var config = [{id:"123",type:"test",credentials:{a:1,b:2}}];
+                var resultingConfig = clone(config);
+                delete resultingConfig[0].credentials;
+                var flow = new Flow(config);
+                flow.getFlow().should.eql(resultingConfig);
+                flow.getMissingTypes().should.have.length(0);
+            } finally {
+                getType.restore();
+            }
+        });
+        
+    });
+    describe('#start',function() {
+
+        it('prevents a flow with missing types from starting', function() {
+            var getType = sinon.stub(typeRegistry,"get",function(type) {
+                if (type == "test") {
+                    return {};
+                } else {
+                    return null;
+                }
+            });
+            try {
+                var config = [{id:"123",type:"test"},{id:"456",type:"test1"},{id:"789",type:"test2"}];
+                var flow = new Flow(config);
+                flow.getMissingTypes().should.have.length(2);
+    
+                /*jshint immed: false */
+                (function() {
+                    flow.start();
+                }).should.throw();
+            } finally {
+                getType.restore();
+            }
+        });
+    });
+    
+    describe('missing types',function() {
+        it('removes missing types as they are registered', function() {
+            var getType = sinon.stub(typeRegistry,"get",function(type) {
+                if (type == "test") {
+                    return {};
+                } else {
+                    return null;
+                }
+            });
+            var flowStart;
+            try {
+                var config = [{id:"123",type:"test"},{id:"456",type:"test1"},{id:"789",type:"test2"}];
+                var flow = new Flow(config);
+    
+                flowStart = sinon.stub(flow,"start",function() {this.started = true;});
+                config.should.eql(flow.getFlow());
+                
+                flow.getMissingTypes().should.eql(["test1","test2"]);
+                
+                flow.typeRegistered("test1");
+                flow.getMissingTypes().should.eql(["test2"]);
+                flowStart.called.should.be.false;
+    
+                flow.typeRegistered("test2");
+                flow.getMissingTypes().should.eql([]);
+                flowStart.called.should.be.false;
+            } finally {
+                flowStart.restore();
+                getType.restore();
+            }
+        });
+        
+        it('starts flows once all missing types are registered', function() {
+            var getType = sinon.stub(typeRegistry,"get",function(type) {
+                if (type == "test") {
+                    return {};
+                } else {
+                    return null;
+                }
+            });
+            var flowStart;
+            try {
+                var config = [{id:"123",type:"test"},{id:"456",type:"test1"},{id:"789",type:"test2"}];
+                var flow = new Flow(config);
+    
+                // First call to .start throws err due to missing types
+                /*jshint immed: false */
+                (function() {
+                    flow.start();
+                }).should.throw();
+    
+                // Stub .start so when missing types are registered, we don't actually try starting them
+                flowStart = sinon.stub(flow,"start",function() {});
+                config.should.eql(flow.getFlow());
+                
+                flow.getMissingTypes().should.eql(["test1","test2"]);
+                
+                flow.typeRegistered("test1");
+                flow.typeRegistered("test2");
+                flow.getMissingTypes().should.have.length(0);
+                flowStart.called.should.be.true;
+            } finally {
+                flowStart.restore();
+                getType.restore();
+            }
+        });
+    });
+    
+    describe('#diffFlow',function() {
+        var getType;
+        before(function() {
+            getType = sinon.stub(typeRegistry,"get",function(type) {
+                // For this test, don't care what the actual type is, just
+                // that this returns a non-false result
+                return {};
+            });
+                
+        });
+        after(function() {
+            getType.restore();
+        });
+        
+        it('handles an identical configuration', function() {
+            var config = [{id:"123",type:"test",foo:"a",wires:[]}];
+            var flow = new Flow(config);
+            flow.getMissingTypes().should.have.length(0);
+            
+            var diffResult = flow.diffFlow(config);
+        
+            diffResult.should.have.property("deleted",[]);
+            diffResult.should.have.property("changed",[]);
+            diffResult.should.have.property("linked",[]);
+            diffResult.should.have.property("wiringChanged",[]);
+        });
+        
+        it('identifies nodes with changed properties, including downstream linked', function() {
+            var config =    [{id:"1",type:"test",foo:"a",wires:[]},{id:"2",type:"test",bar:"b",wires:[[1]]},{id:"3",type:"test",foo:"a",wires:[]}];
+            var newConfig = [{id:"1",type:"test",foo:"b",wires:[]},{id:"2",type:"test",bar:"b",wires:[[1]]},{id:"3",type:"test",foo:"a",wires:[]}];
+            var flow = new Flow(config);
+            flow.getMissingTypes().should.have.length(0);
+            
+            var diffResult = flow.diffFlow(newConfig);
+        
+            diffResult.should.have.property("deleted",[]);
+            diffResult.should.have.property("changed",["1"]);
+            diffResult.should.have.property("linked",["2"]);
+            diffResult.should.have.property("wiringChanged",[]);
+        });
+        
+        it('identifies nodes with changed properties, including upstream linked', function() {
+            var config =    [{id:"1",type:"test",foo:"a",wires:[]},{id:"2",type:"test",bar:"b",wires:[[1]]},{id:"3",type:"test",foo:"a",wires:[]}];
+            var newConfig = [{id:"1",type:"test",foo:"a",wires:[]},{id:"2",type:"test",bar:"c",wires:[[1]]},{id:"3",type:"test",foo:"a",wires:[]}];
+            var flow = new Flow(config);
+            flow.getMissingTypes().should.have.length(0);
+            
+            var diffResult = flow.diffFlow(newConfig);
+        
+            diffResult.should.have.property("deleted",[]);
+            diffResult.should.have.property("changed",["2"]);
+            diffResult.should.have.property("linked",["1"]);
+            diffResult.should.have.property("wiringChanged",[]);
+        });
+        
+        it('identifies nodes with changed wiring', function() {
+            var config = [{id:"1",type:"test",foo:"a",wires:[]},{id:"2",type:"test",bar:"b",wires:[[1]]},{id:"3",type:"test",foo:"a",wires:[]}];
+            var newConfig = [{id:"1",type:"test",foo:"a",wires:[]},{id:"2",type:"test",bar:"b",wires:[[2]]},{id:"3",type:"test",foo:"a",wires:[]}];
+            var flow = new Flow(config);
+            flow.getMissingTypes().should.have.length(0);
+            
+            var diffResult = flow.diffFlow(newConfig);
+        
+            diffResult.should.have.property("deleted",[]);
+            diffResult.should.have.property("changed",[]);
+            diffResult.should.have.property("linked",["1","2"]);
+            diffResult.should.have.property("wiringChanged",["2"]);
+        });
+        
+        it('identifies nodes with changed wiring - second connection added', function() {
+            var config = [{id:"1",type:"test",foo:"a",wires:[]},{id:"2",type:"test",bar:"b",wires:[[1]]},{id:"3",type:"test",foo:"a",wires:[]}];
+            var newConfig = [{id:"1",type:"test",foo:"a",wires:[]},{id:"2",type:"test",bar:"b",wires:[[1],[1]]},{id:"3",type:"test",foo:"a",wires:[]}];
+            var flow = new Flow(config);
+            flow.getMissingTypes().should.have.length(0);
+            
+            var diffResult = flow.diffFlow(newConfig);
+        
+            diffResult.should.have.property("deleted",[]);
+            diffResult.should.have.property("changed",[]);
+            diffResult.should.have.property("linked",["1","2"]);
+            diffResult.should.have.property("wiringChanged",["2"]);
+        });
+        
+        it('identifies nodes with changed wiring - second connection removed', function() {
+            var config = [{id:"1",type:"test",foo:"a",wires:[]},{id:"2",type:"test",bar:"b",wires:[[1],[1]]},{id:"3",type:"test",foo:"a",wires:[]}];
+            var newConfig = [{id:"1",type:"test",foo:"a",wires:[]},{id:"2",type:"test",bar:"b",wires:[[1]]},{id:"3",type:"test",foo:"a",wires:[]}];
+            var flow = new Flow(config);
+            flow.getMissingTypes().should.have.length(0);
+            
+            var diffResult = flow.diffFlow(newConfig);
+        
+            diffResult.should.have.property("deleted",[]);
+            diffResult.should.have.property("changed",[]);
+            diffResult.should.have.property("linked",["1","2"]);
+            diffResult.should.have.property("wiringChanged",["2"]);
+        });
+        
+        it('identifies new nodes', function() {
+            var config = [{id:"1",type:"test",foo:"a",wires:[]},{id:"3",type:"test",foo:"a",wires:[]}];
+            var newConfig = [{id:"1",type:"test",foo:"a",wires:[]},{id:"2",type:"test",bar:"b",wires:[[1]]},{id:"3",type:"test",foo:"a",wires:[]}];
+            var flow = new Flow(config);
+            flow.getMissingTypes().should.have.length(0);
+            
+            var diffResult = flow.diffFlow(newConfig);
+
+            diffResult.should.have.property("deleted",[]);
+            diffResult.should.have.property("changed",["2"]);
+            diffResult.should.have.property("linked",["1"]);
+            diffResult.should.have.property("wiringChanged",[]);
+        });
+        
+        it('identifies deleted nodes', function() {
+            var config = [{id:"1",type:"test",foo:"a",wires:[[2]]},{id:"2",type:"test",bar:"b",wires:[[3]]},{id:"3",type:"test",foo:"a",wires:[]}];
+            var newConfig = [{id:"1",type:"test",foo:"a",wires:[]},{id:"3",type:"test",foo:"a",wires:[]}];
+            var flow = new Flow(config);
+            flow.getMissingTypes().should.have.length(0);
+            
+            var diffResult = flow.diffFlow(newConfig);
+
+            diffResult.should.have.property("deleted",["2"]);
+            diffResult.should.have.property("changed",[]);
+            diffResult.should.have.property("linked",["1","3"]);
+            diffResult.should.have.property("wiringChanged",["1"]);
+        });
+    });
+});
\ No newline at end of file