Of course i've already tried running the game via Glide, it doesn't work. Davros, that link wasn't helpful at all. Obsolete information and not useful because i'm trying to run the game on a modern OS, not XP.
olemogamer: i don't think the "version" of the game is the problem, but rather the OS i'm trying to run it on.
DosFreak: could you test the game in Win7 x64? It's interesting anyway that it works for you under Vista. I think i have an image of my old Vista installation somewhere, maybe i'll try running the game on it just to see if it works. It's a lot of effort for just one old game though (; .
My current "solution" is to play the PSX version with an emulator. It's amazing though how bad the PSX version looks compared to the PC one, even when using advanced rendering options. I'd rather play the game on the PC.
EDIT
DOSFreak: some questions about how you've played/tested the game in Vista: did you disable UAC for testing? Can you remember if you've used any compatibility options on the excutable? Do you happen to know where the game's config files (they are stored in "%windir%\UbiSoft" on XP) were located in Vista?