Nvidia Driver 320.18 and 320.49 is stable?

hi,
Any one using the 320.18 or 320.49 drivers in windows 8?, both the drivers not stable for my system, often the system hangs, mostly when working in firefox. so i go back to 314.22 version.
iam using GTX 560ti GPU with 1GB RAM.

Same for me. But I didn’t try with clean installation. I will do with next drivers.