As you asked; theres probably a performance ou network issue causing this. As JMS is statefull; you have to be conected to the destination conection Factory to consume\Produce any messages.
Any comunication problem, caused by network issues or stability in destination\origin server qould cause the conection to close and therefore; any atempt to use de Queues deployed in the Destination CF would fail. Normal operations resume after JbossMQ conection manager, reconects.
You should look for possible overloads or performance problems in the server running the queue ( probably a few minutes before erros start ). As Jboss 4.2 consoles are very poor; i recomend you install Lambda Probe ( it´s helped me a lot in performance issues ) to help you investigate
link to Lambda probe: http://www.lambdaprobe.org/