Bad news for AzaZPPL

Hey guys i got some bad news about my pc...
my pc is some how crashing when i start to play a game
somehow my graphics card is stopping to work after a limited time
and i am going to call the customer service where i bought the graphics card
so i dont think i will be playing i will be on xfire or steam but i cant really play.
and if any of you maybe can help me with this problem please help me
what happends is that when i start a game after like 15 minutes im getting some horizontal square lines
i researched on the internet what the problem could be some of them say
its my power supply some of them say its about the graphics card
so here are my specs:

AMD Phenom II x4 965 @ 3.84ghz
XFX 4850 512MB DDR3
OCZ Fatal1ty 550W
4GB GeiL Evo Two 1333 2x2
Windows 7 Ultimate 64 BIT
Western Digital 1,5TB 7200 RPM 8MB (im writing this because maybe my Hard Disk stops turning or writing and that maybe cause a problem)

so i hope you guys understand it justgot in to me that i should report this.

1. update your drivers if you haven't i also had problems with the new AMD drivers for some reason had to reinstall them to get them to work properly.
2. maybe your card's cooling is f'ed donwload MSI Afterburner and Kombustor that will allow you to see temps and run some tests.
3.which monitor you have?( problably not the problem if it only happens when the card is stressed)
don't know what else it could be.

1. I cant update drivers from the AMD/ATI site because my graphics card gets F up so i install it from the steam they got the correct version for my graphics card
2. my card is cooling alright because it doesnt go over 60c on load idle 40c
3. i have 2 monitors prolite 2407 and a liteon 15"

try switching monitors but i have no clue what could it be

i searched on the internet for fix and alot of people has the same problem as i do anyway i called the company they said vring the graphics card motherboard and ram to us and we will do a test so i hope it will be fixed soon

Guys i wont be on for a week or so; imma bring tomorow my system to the store that i bought them from i hope they can help me with this annoying problem; well thats it i might post on the forums but idk for sure so

cya guys!