diff --git a/HISTORY b/HISTORY
index 221a1bc4..2c758be2 100644
--- a/HISTORY
+++ b/HISTORY
@@ -8882,7 +8882,7 @@ Video Disk Recorder Revision History
 - Added a short sleep to cTSBuffer::Action() to avoid high CPU usage (thanks to
   Sergey Chernyavskiy).
 
-2017-02-14: Version 2.3.3
+2017-02-21: Version 2.3.3
 
 - Added 'S3W ABS-3A' to sources.conf (thanks to Frank Richter).
 - Fixed a possible deadlock in the recordings handler thread.
@@ -8912,3 +8912,5 @@ Video Disk Recorder Revision History
 - The Setup/CAM menu now only displays master CAMs.
 - Fixed setting the local machine's SVDRP host name (was overwritten if setup.conf
   contained an empty string).
+- PIDs can now be added to and deleted from a cReceiver while it is attached to
+  a cDevice, without having to detach it first and re-attach it afterwards.
diff --git a/ci.c b/ci.c
index 1096721b..8f2256e3 100644
--- a/ci.c
+++ b/ci.c
@@ -4,7 +4,7 @@
  * See the main source file 'vdr.c' for copyright information and
  * how to reach the author.
  *
- * $Id: ci.c 4.5 2017/01/23 11:42:14 kls Exp $
+ * $Id: ci.c 4.6 2017/02/21 14:17:07 kls Exp $
  */
 
 #include "ci.h"
@@ -121,8 +121,6 @@ private:
   int length;
   void AddEmmPid(int Pid);
   void DelEmmPids(void);
-protected:
-  virtual void Activate(bool On);
 public:
   cCaPidReceiver(void);
   virtual ~cCaPidReceiver() { Detach(); }
@@ -156,11 +154,6 @@ void cCaPidReceiver::DelEmmPids(void)
   emmPids.Clear();
 }
 
-void cCaPidReceiver::Activate(bool On)
-{
-  catVersion = -1; // can be done independent of 'On'
-}
-
 void cCaPidReceiver::Receive(const uchar *Data, int Length)
 {
   if (TsPid(Data) == CATPID) {
@@ -208,10 +201,6 @@ void cCaPidReceiver::Receive(const uchar *Data, int Length)
            }
         }
      if (p) {
-        int OldCatVersion = catVersion; // must preserve the current version number
-        cDevice *AttachedDevice = Device();
-        if (AttachedDevice)
-           AttachedDevice->Detach(this);
         DelEmmPids();
         for (int i = 0; i < length - 4; i++) { // -4 = checksum
             if (p[i] == 0x09) {
@@ -228,9 +217,6 @@ void cCaPidReceiver::Receive(const uchar *Data, int Length)
                i += p[i + 1] + 2 - 1; // -1 to compensate for the loop increment
                }
             }
-        if (AttachedDevice)
-           AttachedDevice->AttachReceiver(this);
-        catVersion = OldCatVersion;
         p = NULL;
         bufp = 0;
         length = 0;
@@ -1747,9 +1733,10 @@ cCamSlot::cCamSlot(cCiAdapter *CiAdapter, bool WantsTsData, cCamSlot *MasterSlot
       tc[i] = NULL;
   CamSlots.Add(this);
   slotNumber = Index() + 1;
-  if (ciAdapter)
+  if (ciAdapter) {
      ciAdapter->AddCamSlot(this);
-  Reset();
+     Reset();
+     }
 }
 
 cCamSlot::~cCamSlot()
@@ -1767,20 +1754,28 @@ bool cCamSlot::Assign(cDevice *Device, bool Query)
   cMutexLock MutexLock(&mutex);
   if (ciAdapter) {
      if (ciAdapter->Assign(Device, true)) {
-        if (!Device && assignedDevice)
+        if (!Device && assignedDevice) {
+           if (caPidReceiver)
+              assignedDevice->Detach(caPidReceiver);
            assignedDevice->SetCamSlot(NULL);
+           }
         if (!Query || !Device) {
            StopDecrypting();
            source = transponder = 0;
            if (ciAdapter->Assign(Device)) {
+              int OldDeviceNumber = assignedDevice ? assignedDevice->DeviceNumber() + 1 : 0;
               assignedDevice = Device;
               if (Device) {
                  Device->SetCamSlot(this);
-                 dsyslog("CAM %d: assigned to device %d", slotNumber, Device->DeviceNumber() + 1);
+                 if (caPidReceiver) {
+                    caPidReceiver->Reset();
+                    Device->AttachReceiver(caPidReceiver);
+                    }
+                 dsyslog("CAM %d: assigned to device %d", MasterSlotNumber(), Device->DeviceNumber() + 1);
                  }
               else {
                  CancelActivation();
-                 dsyslog("CAM %d: unassigned", slotNumber);
+                 dsyslog("CAM %d: unassigned from device %d", MasterSlotNumber(), OldDeviceNumber);
                  }
               }
            else
@@ -2014,10 +2009,6 @@ void cCamSlot::SendCaPmt(uint8_t CmdId)
      const int *CaSystemIds = cas->GetCaSystemIds();
      if (CaSystemIds && *CaSystemIds) {
         if (caProgramList.Count()) {
-           if (caPidReceiver && caPidReceiver->HasCaPids()) {
-              if (cDevice *d = Device())
-                 d->Detach(caPidReceiver);
-              }
            for (int Loop = 1; Loop <= 2; Loop++) {
                for (cCiCaProgramData *p = caProgramList.First(); p; p = caProgramList.Next(p)) {
                    if (p->modified || resendPmt) {
@@ -2048,20 +2039,11 @@ void cCamSlot::SendCaPmt(uint8_t CmdId)
                       }
                    }
                }
-           if (caPidReceiver && caPidReceiver->HasCaPids()) {
-              if (cDevice *d = Device())
-                 d->AttachReceiver(caPidReceiver);
-              }
            resendPmt = false;
            }
         else {
            cCiCaPmt CaPmt(CmdId, 0, 0, 0, NULL);
            cas->SendPMT(&CaPmt);
-           if (caPidReceiver) {
-              if (cDevice *d = Device())
-                 d->Detach(caPidReceiver);
-              caPidReceiver->Reset();
-              }
            }
         }
      }
diff --git a/device.c b/device.c
index 2b350e86..0c8b0018 100644
--- a/device.c
+++ b/device.c
@@ -4,7 +4,7 @@
  * See the main source file 'vdr.c' for copyright information and
  * how to reach the author.
  *
- * $Id: device.c 4.6 2017/01/23 11:43:05 kls Exp $
+ * $Id: device.c 4.7 2017/02/21 13:38:01 kls Exp $
  */
 
 #include "device.h"
@@ -451,6 +451,7 @@ void cDevice::GetOsdSize(int &Width, int &Height, double &PixelAspect)
 
 bool cDevice::HasPid(int Pid) const
 {
+  cMutexLock MutexLock(&mutexPids);
   for (int i = 0; i < MAXPIDHANDLES; i++) {
       if (pidHandles[i].pid == Pid)
          return true;
@@ -460,6 +461,7 @@ bool cDevice::HasPid(int Pid) const
 
 bool cDevice::AddPid(int Pid, ePidType PidType, int StreamType)
 {
+  cMutexLock MutexLock(&mutexPids);
   if (Pid || PidType == ptPcr) {
      int n = -1;
      int a = -1;
@@ -524,6 +526,7 @@ bool cDevice::AddPid(int Pid, ePidType PidType, int StreamType)
 
 void cDevice::DelPid(int Pid, ePidType PidType)
 {
+  cMutexLock MutexLock(&mutexPids);
   if (Pid || PidType == ptPcr) {
      int n = -1;
      if (PidType == ptPcr)
@@ -559,6 +562,7 @@ bool cDevice::SetPid(cPidHandle *Handle, int Type, bool On)
 
 void cDevice::DelLivePids(void)
 {
+  cMutexLock MutexLock(&mutexPids);
   for (int i = ptAudio; i < ptOther; i++) {
       if (pidHandles[i].pid)
          DelPid(pidHandles[i].pid, ePidType(i));
diff --git a/device.h b/device.h
index 2639e855..581c187a 100644
--- a/device.h
+++ b/device.h
@@ -4,7 +4,7 @@
  * See the main source file 'vdr.c' for copyright information and
  * how to reach the author.
  *
- * $Id: device.h 4.3 2017/01/09 12:51:05 kls Exp $
+ * $Id: device.h 4.4 2017/02/21 13:23:24 kls Exp $
  */
 
 #ifndef __DEVICE_H
@@ -109,6 +109,7 @@ public:
 class cDevice : public cThread {
   friend class cLiveSubtitle;
   friend class cDeviceHook;
+  friend class cReceiver;
 private:
   static int numDevices;
   static int useDevice;
@@ -355,6 +356,7 @@ public:
 // PID handle facilities
 
 private:
+  mutable cMutex mutexPids;
   virtual void Action(void);
 protected:
   enum ePidType { ptAudio, ptVideo, ptPcr, ptTeletext, ptDolby, ptOther };
diff --git a/receiver.c b/receiver.c
index 8d647c02..dd61fd65 100644
--- a/receiver.c
+++ b/receiver.c
@@ -4,7 +4,7 @@
  * See the main source file 'vdr.c' for copyright information and
  * how to reach the author.
  *
- * $Id: receiver.c 4.1 2015/09/16 11:19:47 kls Exp $
+ * $Id: receiver.c 4.2 2017/02/21 10:59:27 kls Exp $
  */
 
 #include "receiver.h"
@@ -38,8 +38,11 @@ bool cReceiver::AddPid(int Pid)
 {
   if (Pid) {
      if (numPids < MAXRECEIVEPIDS) {
-        if (!WantsPid(Pid))
+        if (!WantsPid(Pid)) {
            pids[numPids++] = Pid;
+           if (device)
+              device->AddPid(Pid);
+           }
         }
      else {
         dsyslog("too many PIDs in cReceiver (Pid = %d)", Pid);
@@ -87,6 +90,8 @@ void cReceiver::DelPid(int Pid)
             for ( ; i < numPids; i++) // we also copy the terminating 0!
                 pids[i] = pids[i + 1];
             numPids--;
+            if (device)
+               device->DelPid(Pid);
             return;
             }
          }