Weird video problems after 1600XP upgrade.

[Mac]

Just installed a 1600xp processor and now have artifacts in all jpg's. Same thing happened when running a mpeg under Media Player. System is Abit KR7A-R, Nvidia GTS 2 and Win98SE. I think all drivers and bios is current. Have not reinstalled the old CPU yet, a AMD 1000/266 Tbird, because did not want to go through the hassle of unlatching HSF and reapplying compound, etc. Artificats are in random vertical and horizantal bands which look like noise.

Hope this is just a simple issue.

Thanks.