I am getting sound from my speakers only with some applications, but not with others. The only thing I can think of that I've changed recently is that I tried to connect my new Snow to my computer, and in doing so I may have altered the settings somehow. I am a complete noob with this synth and its TI system, so I thought I'd run all this past you good people 
Using a Mac Mini running OSX, version 10.6.8 with a MOTU Ultralite mk3, and the same version of GarageBand I have always used.
After hooking up my TI Snow and attempting to follow the first-time setup prompts, I didn't get very far, perhaps because I'm running GarageBand and not some other more capable DAW. (I followed the advice in this thread as best I could.)
This morning I tried to continue, but discovered trouble. I found that playing a streamed song from the Internet comes through my monitors just fine. But playing sound through the MOTU's inputs only comes out through my Mac's small internal speaker. I cannot hear my GarageBand recordings through my monitors either, just the internal speaker.
The Ultralite software's CueMix level meters and EQ display show that the Ultralite is getting sound from its inputs.
No sound comes through the Ultralite's headphones output either, which makes me wonder if it could be the Ultralite itself. I have sent MOTU a tech support request as well.
Do you have any suggestions?