said by Tweakbl:Seems it (Patch 5.1a) has addressed somewhat on the issue.
I am seeing small "Hangs" (Similar to low Framerates) but FPS is good. It will hang at Looting or Loot generation.
I been logged for about 2 hours now doing dailies and it has tried to bomb but not been successful at it yet. (It hangs but then recovers)
How is your memory? Have you run a memory test?
Were you able to remove all your old drivers and reinstall latest?
Video card fan running smooth?