Unmarshalling fails silently

Hello, I'm having a very frustrating experience trying to unmarshal in JAXB. I've compiled classes from the schema without any problem, and I'm able to marshal, send to the server and get a response also. When I try to unmarshal the response into the appropriate class, however, I get a totally silent failure. I posted a thread on Stackoverflow here, which contains formatted code examples. I've spent about 8 hours trying to figure this out, so any help would be greatly appreciated.

Thanks