An Unusable D54250WYK

I have a D54250WYK with 8GB of RAM and a 120GB SSD Windows 7.

The system is really unstable and I can't even use Windows MCE to watch an AVI, XBMC any other application without a blue screen of death.  I've kept all the drivers up to date.  The memory I've used was on the list of recommend types and I've ran memory tests which seem OK.

I've download a demo of a game called Stone Giant as a test and immediately got  a blue screen:

An attempt was made to execute non-executable memory

STOP: 0x000000FC (0xFFFFF88005538000, 0X8000000210FDC1

luafv.sys - Address

I can't think what could be making the system so bad.  Does anyone have any ideas? 

Thanks!

M