are you monitoring the gpu temperatures?
with HWinfo64 for example?
maybe it's temp related thats why reinstalling drivers make them go away for some time (because gpu gets cooller) and reapears when you game,
really wierd issue and if software changes like reinstaling drivers and system doesn't help it must be hardware related (temps perhaps?) or some vbios bug...
Try using Display Driver Uninstaller - it will whipe all previous display drivers leftovers (registry also gets cleaned from them). Get newest version here:
then download and install newest geforce driver
If that doesn't help, 3rd RMA and this time expect to get new unit or motherboard replaced.