Cycles on Nvidia GPU vs. never ending(?) problems

Hi,

I’d like to share some experience re. above subject-i.e. updating to the newest nvidia drivers.
Ive been trying newest graphicall builds (x86_64) - config as states in my footer, till now.
Since some ca. 1 year I noticed degrading CUDA performance, numerous cuda engine errors and finally my whole comp completely(to hardw.reset) stuck on a SMALL GPU render in Blender. I mean really simple scenes (training) - just a few object ,none or few textures, 2-3 light sources.Really.
Ive posted a few times on Blender/Cycles Devs. ticket but it didnt seem to have any influence so I assumed statistically (considering other users) things have to be OK on Blender’s side. Then I started googlin, read about dust buildup inside graphic card’s enclosure, overheating - cleaned whole thing w/no obvious resultetc.etc.
Nevertheless sth told me it started to show the trouble countinously updating nvidia drivers, finally think I found some corelation between CUDA and driver version: in my case 1st driver supporting GPU interface in Blender (2.65 now)
is driver version 270.61 and w/that I have no problems GPU render in the files I could not render in drivers version above that.
In my case (Gigabyte GTX260) its CUDA v.1.3. I will test other combinations but just wonder if other guys noticed similar phenomena ?