diff --git a/src/ca/CASG.cpp b/src/ca/CASG.cpp
index 85fbfecbd..0c1170179 100644
--- a/src/ca/CASG.cpp
+++ b/src/ca/CASG.cpp
@@ -42,6 +42,8 @@ void CASG::destructor (
     epicsGuard < epicsMutex > & cbGuard,
     epicsGuard < epicsMutex > & guard )
 {
+    guard.assertIdenticalMutex ( this->client.mutexRef() );
+
     if ( this->verify ( guard ) ) {
         this->reset ( cbGuard, guard );
         this->client.uninstallCASG ( guard, *this );
@@ -72,6 +74,8 @@ int CASG::block (
     double remaining;
     int status;
 
+    guard.assertIdenticalMutex ( this->client.mutexRef() );
+
     // prevent recursion nightmares by disabling blocking
     // for IO from within a CA callback. 
     if ( epicsThreadPrivateGet ( caClientCallbackThreadId ) ) {
@@ -128,6 +132,7 @@ void CASG::reset (
     epicsGuard < epicsMutex > & cbGuard,
     epicsGuard < epicsMutex > & guard )
 {
+    guard.assertIdenticalMutex ( this->client.mutexRef() );
     this->destroyCompletedIO ( guard );
     this->destroyPendingIO ( cbGuard, guard );
 }
@@ -136,6 +141,7 @@ void CASG::reset (
 void CASG::destroyCompletedIO ( 
     epicsGuard < epicsMutex > & guard )
 {
+    guard.assertIdenticalMutex ( this->client.mutexRef() );
     syncGroupNotify * pNotify;
     while ( ( pNotify = this->ioCompletedList.get () ) ) {
         pNotify->destroy ( guard, * this );
@@ -146,6 +152,7 @@ void CASG::destroyPendingIO (
     epicsGuard < epicsMutex > & cbGuard,
     epicsGuard < epicsMutex > & guard )
 {
+    guard.assertIdenticalMutex ( this->client.mutexRef() );
     syncGroupNotify * pNotify;
     while ( ( pNotify = this->ioPendingList.first () ) ) {
         pNotify->cancel ( cbGuard, guard );
@@ -171,6 +178,7 @@ void CASG::show ( unsigned level ) const
 void CASG::show ( 
     epicsGuard < epicsMutex > & guard, unsigned level ) const
 {
+    guard.assertIdenticalMutex ( this->client.mutexRef() );
     ::printf ( "Sync Group: id=%u, magic=%u, opPend=%u\n",
         this->getId (), this->magic, this->ioPendingList.count () );
     if ( level ) {
@@ -192,9 +200,10 @@ void CASG::show (
 }
 
 bool CASG::ioComplete (
-    epicsGuard < epicsMutex > & cbGuard,
+    epicsGuard < epicsMutex > & /* cbGuard */,
     epicsGuard < epicsMutex > & guard )
 {
+    guard.assertIdenticalMutex ( this->client.mutexRef() );
     this->destroyCompletedIO ( guard );
     return this->ioPendingList.count () == 0u;
 }
@@ -202,6 +211,7 @@ bool CASG::ioComplete (
 void CASG::put ( epicsGuard < epicsMutex > & guard, chid pChan, 
     unsigned type, arrayElementCount count, const void * pValue )
 {
+    guard.assertIdenticalMutex ( this->client.mutexRef() );
     sgAutoPtr < syncGroupWriteNotify > pNotify ( guard, *this, this->ioPendingList );
     pNotify = syncGroupWriteNotify::factory ( 
         this->freeListWriteOP, *this, pChan );
@@ -212,6 +222,7 @@ void CASG::put ( epicsGuard < epicsMutex > & guard, chid pChan,
 void CASG::get ( epicsGuard < epicsMutex > & guard, chid pChan, 
                 unsigned type, arrayElementCount count, void *pValue )
 {
+    guard.assertIdenticalMutex ( this->client.mutexRef() );
     sgAutoPtr < syncGroupReadNotify > pNotify ( guard, *this, this->ioPendingList );
     pNotify = syncGroupReadNotify::factory ( 
         this->freeListReadOP, *this, pChan, pValue );
@@ -222,6 +233,7 @@ void CASG::get ( epicsGuard < epicsMutex > & guard, chid pChan,
 void CASG::completionNotify ( 
     epicsGuard < epicsMutex > & guard, syncGroupNotify & notify )
 {
+    guard.assertIdenticalMutex ( this->client.mutexRef() );
     this->ioPendingList.remove ( notify );
     this->ioCompletedList.add ( notify );
     if ( this->ioPendingList.count () == 0u ) {
@@ -232,12 +244,14 @@ void CASG::completionNotify (
 void CASG::recycleSyncGroupWriteNotify ( 
     epicsGuard < epicsMutex > & guard, syncGroupWriteNotify & io )
 {
+    guard.assertIdenticalMutex ( this->client.mutexRef() );
     this->freeListWriteOP.release ( & io );
 }
 
 void CASG::recycleSyncGroupReadNotify ( 
     epicsGuard < epicsMutex > & guard, syncGroupReadNotify & io )
 {
+    guard.assertIdenticalMutex ( this->client.mutexRef() );
     this->freeListReadOP.release ( & io );
 }
 
@@ -260,6 +274,7 @@ void CASG::exception (
     int status, const char * pContext, 
     const char * pFileName, unsigned lineNo )
 {
+    guard.assertIdenticalMutex ( this->client.mutexRef() );
     if ( status != ECA_CHANDESTROY ) {
         this->client.exception ( 
             guard, status, pContext, pFileName, lineNo );
@@ -272,6 +287,7 @@ void CASG::exception (
     const char * pFileName, unsigned lineNo, oldChannelNotify & chan, 
     unsigned type, arrayElementCount count, unsigned op )
 {
+    guard.assertIdenticalMutex ( this->client.mutexRef() );
     if ( status != ECA_CHANDESTROY ) {
         this->client.exception ( 
             guard, status, pContext, pFileName, 
diff --git a/src/ca/casw.cpp b/src/ca/casw.cpp
index 3725c55cc..5733205b2 100644
--- a/src/ca/casw.cpp
+++ b/src/ca/casw.cpp
@@ -35,10 +35,13 @@
 // Tornado 2.0.1 GNU compiler bugs
 class bheFreeStoreMgr : public bheMemoryManager {
 public:
+    bheFreeStoreMgr () {}
     void * allocate ( size_t );
     void release ( void * );
 private:
     tsFreeList < class bhe, 0x100 > freeList;
+	bheFreeStoreMgr ( const bheFreeStoreMgr & );
+	bheFreeStoreMgr & operator = ( const bheFreeStoreMgr & );
 };
 
 void * bheFreeStoreMgr::allocate ( size_t size )
diff --git a/src/ca/nciu.h b/src/ca/nciu.h
index 3e9b0a251..cd23263b4 100644
--- a/src/ca/nciu.h
+++ b/src/ca/nciu.h
@@ -275,7 +275,7 @@ inline netiiu * nciu::getPIIU (
 }
 
 inline void nciu::writeException ( 
-    epicsGuard < epicsMutex > & cbGuard, 
+    epicsGuard < epicsMutex > & /* cbGuard */, 
     epicsGuard < epicsMutex > & guard, 
     int status, const char * pContext, 
     unsigned typeIn, arrayElementCount countIn )
diff --git a/src/ca/oldChannelNotify.cpp b/src/ca/oldChannelNotify.cpp
index fbf7511f7..f65737d88 100644
--- a/src/ca/oldChannelNotify.cpp
+++ b/src/ca/oldChannelNotify.cpp
@@ -100,12 +100,14 @@ int oldChannelNotify::changeConnCallBack (
 void oldChannelNotify::setPrivatePointer ( 
     epicsGuard < epicsMutex > & guard, void *pPrivateIn )
 {
+    guard.assertIdenticalMutex ( this->cacCtx.mutexRef () );
     this->pPrivate = pPrivateIn;
 }
 
 void * oldChannelNotify::privatePointer (
     epicsGuard < epicsMutex > & guard ) const
 {
+    guard.assertIdenticalMutex ( this->cacCtx.mutexRef () );
     return this->pPrivate;
 }
 
diff --git a/src/ca/sgAutoPtr.h b/src/ca/sgAutoPtr.h
index 8727d78aa..acbab6afa 100644
--- a/src/ca/sgAutoPtr.h
+++ b/src/ca/sgAutoPtr.h
@@ -43,6 +43,7 @@ private:
     T * pNotify;
     struct CASG & sg;
     epicsGuard < epicsMutex > & guard;
+	sgAutoPtr & operator = ( const sgAutoPtr & );
 };
 
 template < class T >
diff --git a/src/ca/syncGroup.h b/src/ca/syncGroup.h
index 3cbed6deb..6fa29608e 100644
--- a/src/ca/syncGroup.h
+++ b/src/ca/syncGroup.h
@@ -274,13 +274,13 @@ inline void CASG::operator delete ( void * pCadaver,
 #endif
 
 inline bool syncGroupWriteNotify::ioPending (  
-    epicsGuard < epicsMutex > & guard )
+    epicsGuard < epicsMutex > & /* guard */ )
 {
     return ! this->ioComplete;
 }
 
 inline bool syncGroupReadNotify::ioPending (  
-    epicsGuard < epicsMutex > & guard )
+    epicsGuard < epicsMutex > & /* guard */ )
 {
     return ! this->ioComplete;
 }
diff --git a/src/ca/tcpiiu.cpp b/src/ca/tcpiiu.cpp
index 490189932..d12651260 100644
--- a/src/ca/tcpiiu.cpp
+++ b/src/ca/tcpiiu.cpp
@@ -1251,7 +1251,8 @@ void tcpiiu::versionMessage ( epicsGuard < epicsMutex > & guard, // X aCC 431
     comQueSendMsgMinder minder ( this->sendQue, guard );
     this->sendQue.insertRequestHeader ( 
         CA_PROTO_VERSION, 0u, 
-        priority, CA_MINOR_PROTOCOL_REVISION, 0u, 0u, 
+        static_cast < ca_uint16_t > ( priority ), 
+        CA_MINOR_PROTOCOL_REVISION, 0u, 0u, 
         CA_V49 ( this->minorProtocolVersion ) );
     minder.commit ();
 }
@@ -1655,7 +1656,7 @@ void tcpiiu::removeAllChannels (
 }
 
 void tcpiiu::installChannel ( 
-    epicsGuard < epicsMutex > & cbGuard,
+    epicsGuard < epicsMutex > & /* cbGuard */,
     epicsGuard < epicsMutex > & guard, 
     nciu & chan, unsigned sidIn, 
     ca_uint16_t typeIn, arrayElementCount countIn )
diff --git a/src/ca/udpiiu.cpp b/src/ca/udpiiu.cpp
index 984922aaf..f6f211ae6 100644
--- a/src/ca/udpiiu.cpp
+++ b/src/ca/udpiiu.cpp
@@ -1257,18 +1257,21 @@ void udpiiu::blockUntilSendBacklogIsReasonable (
 void udpiiu::requestRecvProcessPostponedFlush (
     epicsGuard < epicsMutex > & guard )
 {
+    guard.assertIdenticalMutex ( this->cacMutex );
     netiiu::requestRecvProcessPostponedFlush ( guard );
 }
 
 osiSockAddr udpiiu::getNetworkAddress (
     epicsGuard < epicsMutex > & guard ) const
 {
+    guard.assertIdenticalMutex ( this->cacMutex );
     return netiiu::getNetworkAddress ( guard );
 }
 
 double udpiiu::receiveWatchdogDelay (
     epicsGuard < epicsMutex > & guard ) const
 {
+    guard.assertIdenticalMutex ( this->cacMutex );
     return - DBL_MAX;
 }