Requiem freeze when looking at ball.

[Dunge]

I'm entering level 6 (?) just after the helipad thing and the loading takes longer than usual, and when I get in game I see a ball in front of me with some sparks on it and everything just freeze. Well, it's not completely frozen but I have like 1 frame per 30 second so it take ages only to try to push esc to return to the menu.

I tried to set gfx details all to low and all to maxed up, no difference. I have a 9800gtx and the latest drivers.