diff --git a/core/src/main/java/de/javakaffee/web/msm/RequestTrackingHostValve.java b/core/src/main/java/de/javakaffee/web/msm/RequestTrackingHostValve.java
index 3eb5c5ab..7fcf99a1 100644
--- a/core/src/main/java/de/javakaffee/web/msm/RequestTrackingHostValve.java
+++ b/core/src/main/java/de/javakaffee/web/msm/RequestTrackingHostValve.java
@@ -158,7 +158,25 @@ public void invoke( final Request request, final Response response ) throws IOEx
                 getNext().invoke( request, response );
             } finally {
                 final Boolean sessionIdChanged = (Boolean) request.getNote(SESSION_ID_CHANGED);
-                backupSession( request, response, sessionIdChanged == null ? false : sessionIdChanged.booleanValue() );
+                
+                ClassLoader old = Thread.currentThread().getContextClassLoader(); 
+                //From org.apache.catalina.core.StandardHostValve.invoke(Request, Response)
+                // Bind the context CL to the current thread
+                if( _msmContext.getLoader() != null ) {
+                    // Not started - it should check for availability first
+                    // This should eventually move to Engine, it's generic.
+                    Thread.currentThread().setContextClassLoader
+                            (_msmContext.getLoader().getClassLoader());
+                }
+                try {
+                	backupSession( request, response, sessionIdChanged == null ? false : sessionIdChanged.booleanValue() );
+                }finally {
+                    // Restore the context classloader
+                	if(old!=null) {
+                		Thread.currentThread().setContextClassLoader(old);
+                	}
+                }
+                
                 resetRequestThreadLocal();
             }
 
diff --git a/core/src/main/java/de/javakaffee/web/msm/TranscoderService.java b/core/src/main/java/de/javakaffee/web/msm/TranscoderService.java
index b0db00e4..e09a3f7f 100644
--- a/core/src/main/java/de/javakaffee/web/msm/TranscoderService.java
+++ b/core/src/main/java/de/javakaffee/web/msm/TranscoderService.java
@@ -148,6 +148,9 @@ public MemcachedBackupSession deserialize( final byte[] data, final SessionManag
      * @see de.javakaffee.web.msm.SessionAttributesTranscoder#serializeAttributes(MemcachedBackupSession, ConcurrentMap)
      */
     public byte[] serializeAttributes( final MemcachedBackupSession session, final ConcurrentMap<String, Object> attributes ) {
+    	if(LOG.isTraceEnabled()) {
+    		LOG.trace("Context Classloader - serialize: " + Thread.currentThread().getContextClassLoader());
+    	}
         return _attributesTranscoder.serializeAttributes( session, attributes );
     }
 
@@ -164,6 +167,9 @@ public byte[] serializeAttributes( final MemcachedBackupSession session, final C
      * @see de.javakaffee.web.msm.SessionAttributesTranscoder#deserializeAttributes(byte[])
      */
     public ConcurrentMap<String, Object> deserializeAttributes(final byte[] data ) {
+    	if(LOG.isTraceEnabled()) {
+    		LOG.trace("Context Classloader - deserialize: " + Thread.currentThread().getContextClassLoader());
+    	}
         return _attributesTranscoder.deserializeAttributes( data );
     }