Hi all, I have a Mac Pro mid 2009 and the audio has stopped playing through any source, other than the internal speaker! The sound won't even play out of the headphone port. Here's the scoop. I have these awesome USB speakers: And one day they just stopped working on me. However, they still show up as a valid output in Sound preferences, you could still select the Sound Sticks as usual through the Sound Output preference setting, but they just wouldn't make any noise. So, I put them in my closet and felt very sad about it. Now, a few months later I realize it wasn't just the speakers, the Mac Pro won't play sound through ANY external source, other than it's built in speaker! I confirmed that the Soundstick speakers are working just fine using another mac. Interestingly enough, last night when I specified the "sound effect" output in the Sound Preferences tab to be the USB speakers, THAT works! Now I hear the sound effects through the USB soundsticks again. But it will not play any sound any source other than the Built in speaker, regardless of what's selected. It seems like it must be a software problem but I have no idea what to try or do...? Any advice is greatly appreciated. Thanks!