Penumbra requiem: FPS problem in level 9

[guywithaproblemwithrequiem]

In level 09(closure) i have unplayable framerate while in the rest of levels its okay. I had smilliar problem with power room level but loading up the level again from beggining fixed it, i searched for this and all solutions on this forum didnt work: I loaded previous level(08) and loaded 09 again, i loaded 08 at the end and completed the level again. I cant load 07 because savelog isnt long enough, no other solutions spring to my mind, please help.