Penumbra Scrolling Graphics Problem

[Gert]

Well, I'm on Gentoo AMD64 using the Intel 2.8.0 driver with mesa 7.5 and kernel gentoo-sources 2.6.30-r5 (KMS enabled). I have quite some graphical glitches in Penumbra Overture (objects appearing and vanishing) but otherwise everything runs fine.
Currently, the Laptop is busy, later I'll check back after rebooting to Ubuntu Jaunty to see what's going on there.