570 hd (012-P3-1571-KR) Lock ups in game with flickering artifacts

Having an issue where games lock up/crash with flickering artifacts when enabling control panel 3d settings(ambient occlusion,etc) Also , once temps hit 70-75 is when it occurs. Sometimes I get the driver crashed but has recovered message. 
Video Card Bios version Using nvidia driver version 306.02. 
Have had the same issue with different drivers and have used "driver fusion" to remove old previous drivers. 
Please Help, is this a known issue, defect , etc..? 
Operating System / Microsoft Windows 7 Home Premium Edition 64-bit 
Processors / Intel Core i7 920 @ 2.67ghz 
Motherboard / Intel X58 / MSI MS-7591 
System memory / 12gb DDR3-SDRAM (1333 MHz) 
Hard Drives / Seagate 7200rpm , 500gb / Western Digital Raptor , 150 gb 
Optical Drives / Dvd+-RW 
Video / Nvida Geforce Evga GTX 570 1.25 gb / Gpu Clock 732 mhz , Memory Clock 1900 mhz 
Displays / 20inch Hp Main Monitor / 37inch Dell W3706MC Secondary Monitor

i had this exact problem with my 550 ti. but when i got a new card, i never got the problem again. i believe its a gpu defect