HD4850 and possible aero crash

[Kronos_76]

I've been having random crashes that I think are related to my 4850 and Vista Aero. My computer will randomly lockup forcing a reboot, it seems related to resolution changes and/or video playback but nothing definite. The crashes are random, but happen 1-2 times a day. All my gaming works fine however. Here's what I'm running:

Core2Duo E8400 3.0ghz
ASUS P5E3 premium @wifi latest 803 bios
Gigabyte 485OC radeon HD4850 1gb
4gb OCZ RAM (2x2gb)
Soundblaster X-Fi Titanium
Sony DVD RW
1tb WD Caviar Black HDD
Antec 850W PSU
Windows Vista64 SP2

I've unistalled and reinstalled Vista twice, updated all the bios/drivers I could find. If I put my old GeForce 7800GT in the system it works fine, if I put the Radeon in an older system running XP it seems to work fine, and if I turn Aero off the crashes seem to go away. I can live without aero if that's the problem, but it irks me that I can't figure it out for sure. Tempted to by an NVIDIA card since I've had multiple driver problems with ATI/AMD over the years

 

[Kronos_76]

Oh, and I've already completely dissambled and reassembled the computer, cleaned it, checked cables, etc... all the routine stuff when trying to diagnose a hardware problem. memory passes memtest, computer runs prime95 for hours with geforce in it. temps are all good too, idles at 40C peak at 50c for card, cpu similar temps, thanks

 

[Kronos_76]

I ended up buying a new 4870 card. Had to enable/disable PEG Port force x1 setting in bios. Initial install had the same crash, but after turning down PCI from x16 to x1 and back again seems to have fixed it, maybe that's all it needed. Spent a lot of $$ tracking down a bios setting it seems.