Edirol ua-1a crashes GB

A couple years ago I used a setup for playing my guitar with a MobilePre USB as the input from the guitar and out put going along with the iTunes feed out to my sound system via an edirol ua-1a unit. I would get sound from both iTunes and my guitar so I could play along. I'm trying to set up this system again but when I change the audio out in GB preferences, GB crashes. It will output thru the Built-in audio, but not the edriol ua-1a. Anyone have any suggestions?