Yeah, post your chipset, CPU, mobo etc. Are you overclocking CPU or the Radeon? Is your case particularly hot? I personally think that one of the stupidest things in computer design today is that AGP cards face into the bottom of your computer!!! How silly is that?? Esp when most of them have biga** HSF's on them these days...
If you want the latest drivers, or more helpful help
I can recommend the forums on
www.rage3d.com They are a friendly bunch of ATi product owners...
and generally fairly good at solving problems (most ppl there have had more than a few)
And Fool, ATi's drivers are sooooooo much better than when the Radeon was released!! I think that soon ATi owners will be laughing at everyone with Geforce's etc... j/k