These cards, they are originally not 'intended' for compute work, so they start mining in P0 state and then, after a short period they switch back to P2 state and that messes up all overclock speeds and whatnot.
Therefor it is a good idea to disable this "Force P2 State" feature for mining.

• first of all! Stop any miners
• choose mem +0, core +0 overclocking in MSI Afterburner
• in your RainbowMiner directory, goto "Includes\NvidiaProfileInspector"
• start program "NvidiaProfileInspector.exe"
• when you are running that, go down to section 5: there is a setting "CUDA - Force P2 State". Set this to "Off" and click "Apply Settings" button on the top right.
• now your cards should be able to work and stay in P0 state
• important: the reference levels for overclocking are now shifted. You will have to redo all your overclocking profiles, so that you do not run the cards out of their limits.

A last note: everytime you update the Nvidia drivers, the "Force P2 State" will be reset to "On", again. Do not forget to use NvidiaProfileInspector.exe to set it to "Off" again.

RBM