This is the first time it happened and I don't know if it is reproducible but I hope my bug report helps.
My performance based on the questions in the performance topic is:
What changed for you from the last patch (Performance wise)
Nothing, it got worse
What are your video settings, did you change them since last patch?
Custom all low with AA on.
Average FPS ingame and in the menus for previous patch and latest patch (Press F9 to see your FPS)
Average between 10 and 25 (serious) this has been leaning more to 10 after the last patch. Menu's are fine.
System specs
I7, nvidia gforce gt330M, 6gb ram, fast SSD, windows 7, latest drivers for all hardware.
Information about your internet connection / Geographic location
50 mbit up and down fiber connection from the Netherlands
Your personal impressions
the last performance improvements are not applicable to me since it got worse.
Edited by Mitta, 22 November 2012 - 04:09 PM.