Hi snorkelfisk,

1.Is there any other messages can be processed? Or all the messages you put into queue always get stuck? If so, this case you should check whether MDB properly deploy or not.
2.If MDB deploy is ok and some other meesages can be processed. It would be possible that MDB get some system exception while processing those messages and return it back to the queue.

If this is the case, there are 2 options,

the fisrt is modify MDB to have try catch block for the statements that be possible to throw system exception, when it got exception you just log it to the log file and don't rethrow it to the caller.
 
The second is easier, you can configure jms queue to be deleted or send to other queue after it get exception. you can also set retry count for the queue.

Hope this help,
Sompol