Also having this problem running a GTX660Ti.

Sometimes I get no "display driver reset" for hours, other times I get them every 10 minutes. The screen will turn black for a few seconds and when I get a picture again my framerate dropped to ~9fps which makes evading boss moves as tank almost impossible.
Tabbing out and back in again solves the problem sometimes, other times I'll have to tab 10+ times (group usually wiped by then) before things run normal.

I tried stress testing every component I can, tried different driver versions and also tried playing around with ingame and driver settings.
The only thing I noticed was that I had less problems when turning my settings low (just resolution at standard 1920x1080).

My previous card was a Radeon 5850 and I never had any issues with it no matter which driver version or game.
The first time I heard a word of TDR errors was after these errors started to happen with the new card.
It's also the first card where Firefox crashes randomly.