GTX295 stuttering?

[Barso]

I am playing world of warcraft and getting stuttering with my GTX295.
I have the latest drivers and my HDD has been defragged.
I have single GPU mode and have tried the new 190 and the 186 drivers but I still get that stutter.
The framerate analysis is showing a constant 60FPS as I have vsync on but that annoying stutter is still there.
I have also used HD tune on my HDD and it shows it as being healthy.
I wish I got a GTX285.

[Earzz]

Whats your PSU?

[Barso]

Tagan piperock 1100.
What is the best way to tell if the PSU might be faulty?

[Asylum1]

Whats your PSU?

That would be my first question also.
Its either not getting enough power or sounds like a driver issue.
Did you uninstall old drivers before installing new ones?
Try driver 186.18