radeon 9600xt problem. pls help!!

i have tried to solve this problem over and over again. i need help figuring this out. i ordered a radeon 9600xt 256mb RAM about a month ago when i installed the card everything would run fine except when i tried to play games. the textures would go all crazy or the game would just exit. i called ati and was eventually told the card must be bad, so i sent the card back and got another. well this time the card just randomly reboots even in windows now and i cant even load the games without a crash. i switched back to my old card and everything worked fine with all the same drivers and settings as with the new card. i even reset my bios and started from scratch with the new card and it still did all this. i dont know what to do. i have updated all the drivers, the bios, the motherboard - everything- and made sure all irq's are not in conflict. i have a 2.4 ghz 533 fsb. the motherboard is syntax p4svx400-l and i have 1g of pc3200 RAM which has been tested also and is good. also have audigy 1 platinum. is it possible that i got 2 bad video cards in a row? or do i have a compatibility issue somewhere?

1) do you OC your coputer at all?
2) What drivers are you using?
3) what PSU do you have?

no i dont OC anything. 2- which drivers are you asking about? i have updated everything and told my specs above. 3- whats a PSU?