Did they actually manage to de-optimize the game?

Before the recent patch I always had a pretty good framerate. I didnt check it very often, but from the fact that I had no problems with it, I'm assuming it was at least above 40-50. Suddenly after this latest patch my normal framerate when standing still doing nothing has dropped to 30, and if I dare go into combat it sometimes drop below 20. This is with the exact same setup and exact same settings.

How did they even manage to do that?

Edit: Ok what is going on. I alttab back into the game, same settings, same everything, and go back to the map I was in previously. Suddenly my fps is now spiking above 100. This is actually bizarre.

Edit2: Alttabbed back into the game and fps is back to 30. It seems this problem is related to alt-tabbing. Alt-tabbing inside a map will kill my fps, but rezoning will restore it.

What are your system specs? Are you using an ATI/AMD card?

Yea, I'm using a 5870. Haven't had any problems until now, however. I also seem to have isolated the problem to something to do with alt-tabbing.

What drivers for your graphics card are you using?