i have'nt had any problems with my mac mini until a few hours ago when the songs playing started to echo and go weird. so i closed itunes and opened it again, same problem, so i reboot and now there is no sound at all, and when i check the sound preferences it says there is no device to emit sound, (not even the little internal speaker) and i cant find any drivers for sound!, the apple hardware test hasnt noted any problems though, so i was wondering if anyone here can help me fix it, or will i be forced to reinstal os x. thanks 