What drivers are you using? what sdk? What miners? You're using the same os as me so it cant be that, and i dont thin kthe card difference should do anything since you're using 2 diffrent cards as am i.. this is so frustrating. It's not an option to use 2.1 sdk either because for some reason guiminer as well as phatk 2.0/2.1/2.2 won't run with sdk 2.1
11.6 / 2.4
I had an issue where after a few different driver installs, in which I had to use Driver Sweeper to clear out the old files.