Im having the same kind of problem. Altho mind kinda started off defintely.
I recently a 7600 GT into a brand new computer setup (3.0 duo core cpu, 2 gigs of Ram, 650W Antec PSU, biostar motherboard TP43D2-A7), after my last computer died (ethier virus corrupted the bios/paritions not sure). Anyway, for the last week or so everything was fine, i was doing backups and recovery of my old IDE drive so i wasnt using the computer for much in terms of power (ie no gaming, apps, etc).
Ok so today i decide im done trying ot back up, and start installing apps and my game. No problem again. So i boot up Planetside start changing the resolution in the game to match my desktop and its all good. Then i notice my sound isnt coming out, so im thinking i didnt connect it right. So i pull the plug out and put it back in another slot. I hear a crackle of static as the plug hits the other slot and suddenly Planetside goes crazy with graphical glitches. I manage to control alt delete out and kill the program. Ok so after that i try the onboard audio ports (and some Realtec software pops up). After trying that i hit one more onboard port and the computer just freezes up, crashes, and reboots.
Now while rebooting, my startup BIOS screen suddenly has little redlines all over the place. Get to windows, and the windows startup screen has little blue lines all over it. Then the display goes black and nothing happens. My monitor powers off like i had shut the computer off. I hard boot it, same thing happens. I hard boot it again, go into Windows safe mode and im able to get in (clean screen). So reboot again (no changes) and black window death. So back to safemode, remove the nivida drivers and im able to get back into Windows. Install older drivers, black window death. After remvoing all nivida drivers im able to get back into regular windows. Sometimes ill get pixelled corrupting and sometimes not. Im pretty much at a lost of what to do here.
I read a few sites talking about not enough power for the 7600 (said it needed 20A on 12v). I noticed the specs on my new PSU shows (i think) 19A on 12vs. I doubt the sound cables had anything to do with it, i think it was just bad timing after trying to run my graphic intenstive game. Im about to try my old card (if i can fit it in, which i doubt) and see what happens. My guess is my card is bad and it seems to hit the bad spots at random times.
Any thoughts would be greatly appericated, thanks in advance.