no sound out of monitors

Sorry if I'm double tapping on this question, but can't find the answer. I installed pt10 on my mac pro 2006, os 10.7 with digirack 003+. I did a test record but noticed nothing wad coming out of my monitors, nor during playback. Software picks up the digirack, all setting are at default, in stereo, analog 1-2 going to one left and one right. Any thoughts or where I can find the trouble shooting methods?

Thanks