SOLVED)
1. Download MSI afterburner or EVGA Precision or Riva Tuner
2. Under clock your GPU by atleast 50Hz (GPU and memory clock)
3. Save your settings (profile)
4. Play any game without hiccups
I have tested this and i am happy to say that my laptop is crash free on BF3 for over 4 hours now.
P.S : Under clocking decreases the performance a bit :(
... but it also reduces the GPU temp and power consumption :)
You can also try installing a custom BIOS with GPU clock control, but my method works without hiccups.
Sorry for such a delayed solution... hope it helps fellow XPS brothers
BTW : I have a friend in Dell, he said that this issue is caused by error on Nvidia's part to properly set the 'failsafe' limit on the GPU and not optimizing their core clocks. It is this failsafe that triggers the freeze to prevent further damage to the GPU. But he did suggest that a fresh layer of thermal paste would perhaps solve it also.