Index: tomcat/src/main/org/jboss/web/tomcat/service/session/SessionBasedClusteredSession.java
===================================================================
--- tomcat/src/main/org/jboss/web/tomcat/service/session/SessionBasedClusteredSession.java	(revision 89288)
+++ tomcat/src/main/org/jboss/web/tomcat/service/session/SessionBasedClusteredSession.java	(working copy)
@@ -146,7 +146,7 @@
     */
    public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException
    {
-      synchronized (this)
+      synchronized (getSession())
       {
          // Let superclass read in everything but the attribute map
          super.readExternal(in);
@@ -164,7 +164,7 @@
     */
    public void writeExternal(ObjectOutput out) throws IOException
    {
-      synchronized (this)
+      synchronized (getSession())
       {
          // Let superclass write out everything but the attribute map
          super.writeExternal(out);
Index: tomcat/src/main/org/jboss/web/tomcat/service/session/JBossCacheClusteredSession.java
===================================================================
--- tomcat/src/main/org/jboss/web/tomcat/service/session/JBossCacheClusteredSession.java	(revision 89288)
+++ tomcat/src/main/org/jboss/web/tomcat/service/session/JBossCacheClusteredSession.java	(working copy)
@@ -113,21 +113,24 @@
    /**
     * Increment our version and place ourself in the cache.
     */
-   public synchronized void processSessionRepl()
+   public void processSessionRepl()
    {
-      // Replicate the session.
-      if (log.isTraceEnabled())
+      synchronized (getSession()) 
       {
-         log.trace("processSessionRepl(): session is dirty. Will increment " +
+         // Replicate the session.
+         if (log.isTraceEnabled())
+         {
+            log.trace("processSessionRepl(): session is dirty. Will increment " +
                    "version from: " + getVersion() + " and replicate.");
-      }
-      this.incrementVersion();
-      proxy_.putSession(realId, this);
+         }
+         this.incrementVersion();
+         proxy_.putSession(realId, this);
       
-      sessionAttributesDirty = false;
-      sessionMetadataDirty = false;
+         sessionAttributesDirty = false;
+         sessionMetadataDirty = false;
       
-      updateLastReplicated();
+         updateLastReplicated();
+      }
    }
 
    /**
Index: tomcat/src/main/org/jboss/web/tomcat/service/session/ClusteredSession.java
===================================================================
--- tomcat/src/main/org/jboss/web/tomcat/service/session/ClusteredSession.java	(revision 89288)
+++ tomcat/src/main/org/jboss/web/tomcat/service/session/ClusteredSession.java	(working copy)
@@ -815,7 +815,7 @@
       if (expiring)
          return;
 
-      synchronized (this)
+      synchronized (getSession())
       {
          // If we had a race to this sync block, another thread may
          // have already completed expiration.  If so, don't do it again
@@ -1212,7 +1212,7 @@
    public void readExternal(ObjectInput in) 
       throws IOException, ClassNotFoundException
    {
-      synchronized (this)
+      synchronized (getSession())
       {
          //    From StandardSession
          id                  = in.readUTF();
@@ -1284,7 +1284,7 @@
    public void writeExternal(ObjectOutput out) 
       throws IOException
    {
-      synchronized (this)
+      synchronized (getSession())
       {
          // From StandardSession
          out.writeUTF(id);