Windows 7 BSoD ATI HiS 5850?

I'm getting frequent blue screens no matter what I run on the system. I believe it may be a graphics card fault/faulty graphic card drivers. Take a look at the minidump:

======================================…
Dump File : 122211-25521-01.dmp
Crash Time : 2011-12-22 22:19:17
Bug Check String : SYSTEM_THREAD_EXCEPTION_NOT_HANDLED
Bug Check Code : 0x1000007e
Parameter 1 : ffffffff`c0000094
Parameter 2 : fffff880`049d84fd
Parameter 3 : fffff880`02ee3fa8
Parameter 4 : fffff880`02ee3810
Caused By Driver : atikmdag.sys
Caused By Address : atikmdag.sys+f6659
File Description :
Product Name :
Company :
File Version :
Processor : x64
Crash Address : atikmdag.sys+f74fd
Stack Address 1 :
Stack Address 2 :
Stack Address 3 :
Computer Name :
Full Path : C:\Windows\Minidump\122211-25521-01.dmp
Processors Count : 4
Major Version : 15
Minor Version : 7600
Dump File Size : 275 712
======================================…

Any suggestions?

My specs:
Win7 64bit
Ati Radeon 5850 (no OC)
Intel Q6600 (no OC)
Kingston 4gb ram
650W Corsair PSU
Asus P5K mobo

HELP!
 
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