Quake 4 & Doom 3 lockup with HD4870..

Topic pretty much sums it up. On top of that, I figured with my VisionTek HD4870 (512mb) I should have no problem cranking these games out at full-blast with great framerates, seeing as I was able to do it relatively well with my 7600GS card a year ago.

Even so, Doom 3 at 1280x1024 with 8xAF and 4xAA on Ultra Quality dips into the 40's sometimes!! I figured this game would be glass-smooth!! Quake 4 seems much better... but that's really not the issue..

..the problem is that, sometimes within 30 seconds, sometimes after 10 minutes, the screen just freezes and the windows mouse pointer becomes visible. I have to Ctrl+Alt+Del out of the game to find that it's "stopped responding". I don't even have to be PLAYING, because this happens in the menu screen too. This never happened before with my old GeForce 7600GS and I just recently re-installed the games (with their latest patches of course). It's the same problem with Doom 3 and Quake 4.

System specs are:

Q6600 @ 2.8ghz
Vista 32 bit
2x 1GB DDR2-667
H4870 (512mb)
650watt PSU
X-Fi ExtremeGamer

CPU temps stay cold (upper 40's Celsius), GPU temp never goes over 70*C while playing.

FWIW the rig plays Crysis at 1440x900 with 8xAF and 0xAA with the CCC 2.21/ToD mod on level 5 and I average around 38fps so I really doubt it's a matter of the system being overtaxed.

Any ideas?

Dave

Possibly patch games to latest version.