I have found out what the problem is. In the socket class I had a timer. If the socket class is not termination is not trapped within the class, (a class dispose event would be great), the timer is left enabled and this appears to be the sleeping thread, by removing the timer the Sleeping Thread is not created.
When the client connection terminated, I would have expected my astmClient_Terminated event to fire which would have allowed me do the class cleanup.
Thoughts views would be appreciated.
BTW I am using Beta 5
Edit: The astmClient_Terminated was named incorreclty should have been aStream_Terminated