very unstable game

[Trydi]

Hi. I have problem with Penumbra : Black Plague. I have ATI Xpress1250, and when i play, i have some problems. First - many times, i don't see some textures, or see strange textures (sometmes not normal, but black). Many times, when i turn on flashlight, i don't see their light. Games many times crash (or freeze), and back to Gnome, when level's are loading. I feel, like im playing in some Beta versions - not normal version. Is there maybe some patch, or upgrade for linux version of Black Plague? Im using Ubuntu 8.04, and i have graphic driver from system repository.

P.s: sorry for my bad english, because im from poland.