the example I have is that. when a simple copy command is been sent to the file server it gets blocked and the communication between SQL and file server gets fails causing a que on the rest of the nodes which then is forcing the software we are working on to freeze. From looking at the profiler on SQL this AutoNested was showing up in the time frame from which this the whole process froze. It was only happening in the Master database.

then it seems to unblock its self after about 10 minutes on the both occasions its happened.