I've been reading up a lot about ATI 5xxx cards having the grey stripes crashing issue, but it seems that they all happen to people when the PC isn't under any specific video stress. I have the same problem, only that it happens when the video card is under significant video stress, i.e. shattered horizon, left 4 dead 2, "oh i was just playing around with x24 super sampling", etc. Which makes me think that it isn't the same problem. Another factor is that my PC did something similar to this before i got the 5870, with an nvidia 8800 GTS 512, however instead of grey stripes it would just be a black screen and it would take much more stress to cause it.
My current build:
Intel Core 2 Quad
Extreme Q6850 @ 3.00GHz
ASUS Striker Extreme Motherboard w/LGA775/Nvidia nForce 680i SLI (v.1901 BIOS)
G.skill PI Black 2GB DDR2 800(PC2 6400) RAM x4
XFX ATI Radeon HD 5870 (XXX edition)
Creative SoundBlaster X-fi Titatium Fatality Pro
x1 Western Digital Caviar Blue 500gb
x1 Western Digital Caviar Green 1TB
BFG Ageia PhysX Physics processor (128mb)
Windows 7 Ultimate x64
My current build:
Intel Core 2 Quad
Extreme Q6850 @ 3.00GHz
ASUS Striker Extreme Motherboard w/LGA775/Nvidia nForce 680i SLI (v.1901 BIOS)
G.skill PI Black 2GB DDR2 800(PC2 6400) RAM x4
XFX ATI Radeon HD 5870 (XXX edition)
Creative SoundBlaster X-fi Titatium Fatality Pro
x1 Western Digital Caviar Blue 500gb
x1 Western Digital Caviar Green 1TB
BFG Ageia PhysX Physics processor (128mb)
Windows 7 Ultimate x64