RADEON 9800XT artifacts

Hi, I have a big problem with my RADEON 9800XT graphics card, when I play a 3D game, after a few minutes on the screen appears a big ammount of artifacts, it starts being small yellow dots and after few seconds appears a strange triangle polygons with one vertex on the center of the screen and the game becames unplayable (http://perso.wanadoo.es/rt003va5/index.htm). When tuis occurs if I return to windows desktop and I return to the game these polygons disapear and appear after few seconds.

Let me show you my computer configuration:
-Intel P4 3,02GHz
-RAM 2x512Mb Kingston
-MainBoard ASUS P4C800Deluxe
-Graphics card Club3D ATI RADEON 9800XT 256mb AGP
-Windows XP SP2
-Drivers ATI CATALYST 6.9

Isupposed this was caused by high temperature of the graphics card, so I bought a ZALMAN cooler (VF700-AlCu) (http://www.zalman.co.kr). After installing it at first time the artifacts disappeared, but few days ago they returned!! The temp of the graphics card does not exceed 72ºC.

Thanks for your answer but no, it doesn't solved anything

maybe the temp has decreased some degrees but the artifacts are still there I think I'll have to buy a new card, can you recomend me a good AGP card?

Either one of these would be a big upgrade. That X850pro is a great deal.

http://www.newegg.com/Product/Prod [...] 6814102042

http://www.newegg.com/Product/Prod [...] 6814102606

I recently bought a nvidia 7800gs, it's a good card, but now i have a problem with the dvi output, there's no out signal but if i connect it on the analog output there's no problem, if I use an dvi-analog converter it works perfectly. Anybody know why is this happening? is a problem of the dvi wire I'm using?? or is the card broken??

I don't think so, with my old Radeon 9800xt it worked perfectly...I think is the card