9800gtx+ causing problems....help please

ok i just recently bought a bfg 9800gtx+ and while im playing call of duty wow the game freezes and the pixels get all messed up and i cant even use alt control delete and i have to shut down my system....this happens after playing for about 30 min and i never had these problems with my previuos graphic cards which were dual 9800gt's... NEED HELP PLEASE

my specs
xps 630
e8500 @ 3.8
4gb @ 800mhz
bfg 9800gtx+
650i motherboard

how do you do that

well i decided to return the card and i am going to get a new one.....do you have any suggestions in what graphic card i should i get? do you noe which one would work on my dell xps 630

Yeah why would you downgrade from 2 9800GT's to a single 9800GTX+??

So basically you returned the card because your too lazy to install your drivers correctly. Its morons like you that cause people like us to have to pay restocking fees.

Now you want us to recommend a new miracle card for you that will work while you have old and new drivers installed at the same time, lol, good luck.

yea i was gonna go sli with the gtx+ ....duhh lol ..but i had a bad card whenever i played any of my games after 30 min the pixels would get messed up and then my computer would lock up and that was after reinstalling the drivers and doing that driver cleaner...so im gonna return the 9800gtx+ and buy a gtx 260 and then add another one later on i think thats good...right?

yea i hate dell...but where do i do to delete the old drivers and do i do it before i install the graphics card? or do i do it after