ATI 5830 Blackscreen/Artifacting

I've been using my ATI Radeon 5830 for almost 2 years now. I don't overclock anything in my PC. Lately I've been having a problem with my screen going black. At first this was only when I would be playing Diablo III. It's usually followed up by me force restarting, and I usually have to do this about 2 times because my display sometimes doesnt come back when i turn it back on. This might be a good time to note that I'm using an HDMI connection, and I have tried using different cables during the blackscreening.

Here's the weird part: I was originally thinking the card was just overheating. But sometimes I'll come home, turn the computer on, and still get a blackscreen before I even finish booting up, when it's not even under load. And then it's usually followed by artifacting on my desktop and the driver will stop working a couple times til the artifacting goes away. I've checked temps during this happening and it was always in the 40-50's area, (idle at 36) not high enough to be a heat issue still.

I'm an intense gamer and I sometimes launch Battlefield 3 for a good 4-5 hours and I've NEVER had this issue. Not even during other games, just Diablo III, and then it follows up with all the symptoms above, artifacting on reboot, multiple reboot attempts before display coming back, occasional BSOD that will go away in 2 seconds.

I've done Memtest86 on both of my sticks of ram, they came up clean. I did a furmark test on my card to try and recreate the situation but it passed after leaving it on for 20 minutes. I read it could be a PSU issue so I tried to download Hardware monitor, sadly the +12v rail did not show up, but it did show up in my BIOS, where it idled at 12.091 and occasionally dipped to 12.038.

The only conclussion I can come up with is the latest drivers making my card go insane, but I'd rather be safe than sorry. Any thoughts/suggestions would be greatly appreciated.

Specs:

Windows 7 x64
i5 2500k
ASRock z68 Extreme3 Gen3 mobo
4 gigs ram @ 1600 dual channel
ATI Radeon 5830 XFX brand
650 Watt PSU