Just installed Dusk HD for the first time. In the very first room on the very first level, as soon as I crouch (anywhere in the room) I fall through the map as if I'd turned on no-clip mode. Every time. Doesn't matter where I'm standing. Sometimes I land "on top" of some other map feature and can walk back into the first room and continue. Sometimes I plunge to my death thereby ending the playthrough (and the game).

Anybody else experience this? (Seems a pretty obvious bug to have gone unnoticed.) Any idea how to overcome it?