Ok, so I've been serching for the last couple hours and haven't found much in the way of an answer to this particular problem.
The sound in my rear speakers seems to have stopped working, except not really.
My setup is an intel mac-mini in my car running bootcamp to an external usb sound blaster live, then to my 4 channel amp and out to my 4 speakers.
Now, if I'm in Creative's speaker test app, and I have it on 4/4.1 then I can hit either the channel or noise test and hear all four speakers announce their presence (i.e "front left....front right... etc...").
However, when listening to anything out of my front end (Centrafuse) or anything else (like sirius plugged into the line in of the sound blaster) then only the front speakers work.

This has me totally baffled, and nothing I've tried (uninstalling/reinstalling the sound card and drivers, messing with the control panel settings etc..) has fixed it.
Since the creative app tells me the speakers are working, I know it must be some sort of conflict in software, but I can't think of what it could be.
I think that's the most smilies I've ever used in a post. Anyway, does Anyone have any ideas??