I have read the instructions before posting the question, but I'm only able to provide the info I did already since the exception is happening at ramdom as I have said, so I'm not able to provide the full stacktrace nor the trace of the exchanged stream elements.
That sounds like your application is not logging uncatched exceptions. May I recommend installing an uncaught exception handler? See Thread (Java Platform SE 7 )
The trace doesn't appear to be important in this case. What's important is the exception, the stacktrace and the exact used smack version.