I have a Diamond ref in RMA right now because at idle volts it gives lines on the screen, but when its at stock volts, 1.175, it works fine. So when im surfing the web or something i get lines on certain parts of the windows.
Edit: better way to say it is when it down clocks to .975 I have problems. When i use constant voltage in Afterburner, and set volts to at least 1.1v its just fine.
Now I am only suspecting the PSU or the GPU. After identifying on another computer I'll just have to RMA what is not good.