DescentBB

Well I think things are finally under control. I was having problems with game crashes but I think I finally resolved the issue. After trying the disable the VPU recovery mode in the ATI control panel, along with disabling "Use DDC Information" as suggested by the Omega guy and no luck there, I went to the ATI site and got a few more nuggets of info.
In bios, I had the AGP aperature command I had it set to 256 ( 1/2 of system ram). ATI said to set it at 64.
Also under Dram timing I changed the Fast Command from ultra to normal. I made both these changes at the same time so I don't know if one or the other was the key but at least I can now play the UT4 demo with no crashes.

That's great news you got your computEr fixed!

I seriously doubt the AGP aperture size will cause game crashes. To me it sounds like your RAM timing was too agressive - causing errors. ANY memory error will result in the application crashing.

No need to change your AGP aperture size now I suspect - given that no games use that aperture unless the game has more textures than will fit in the GFx card memory.

Happy computing.

Oh, and for any RAM overclocking, it always pays to download and run the MEMTEST application which finds errors in RAM modules. Test the system RAM for at least 12 hours solid before announcing it to be "stable".