Might be.....

1. Inadequate PSU.
2. Defective card
3. Heat

I'm leaning to defective card...


couple of possible fixes...:
1. Run GPU-Z and find the cards maximum temperature during OCCT graphics (GPU) test. Anything over 100C is bad. If so, update cooling.
2. Run Rivatuner and underclock the card... i.e. core, shader, and memory clocks by 100mhz.  If the card is defective this might eliminate the problem. If so, return the card (don't tell them you were changing clockspeeds though..)
3. Try in another computer.
4. Update drivers.
5. Run OCCT graphics test for an hour. Then.... run OCCT POWER SUPPLY test for an hour. If it works on the graphics test, but not the power supply test, then it is the PSU.

This might not find the problem, in which case it's probably best to bring it into a respectable PC store.

I am going on holidays so I won't be on for over a week..

Ok latest news.
As we speak im having fs2004 working window mode, level d 767 circling around egll pro. with REX 2004.
on the frist run i was pushing back and it quit like 4 min after fs start.
Now it as been almost 6 min at 6000ft cirlces and this is what gpu-z reads

GPU CORE CLOCK- 625 MHZ
GPU MEM  CLOCK - 900MHZ
GPU SHADER CLOCK- 1566 MHZ
GPU TEMP - BETWEEN 62 AND 63 C
PBC TEMP. - 45 C
GPU TEMP. - 55.8 C
FAN SPEED- 30%
FAN SPEED 1700 to 1780 rpm

So far still running if it quits i will try to see , how long it took and temps.