So BioShock ROCKS. Ok, we know that.
Now for the issues...
I tried the demo back on my 6600GT AGP card a while ago, and figured it couldn't run (or look nice enough) with that card. So I uninstalled it.
Then I bought the retail version on my last upgrade, and had some issues with it.
I did some WinDbg debugging, some cleanup, chkdsks, etc and now the PC stopped crashing.
After a while, 30% of the game started showing with black textures, as if the lighting was messed up. Even worse, some characters (and bots/turrets) showed invisible textures, which made it very, VERY frustrating to play (I am walking happily, then suddenly I start getting my health all drained up. Guess what? Invisible enemy).
So I looked in forums all over, found nobody with my exact problem. Tweaked the hell of all the available .INI files in the games. Until I found a solution buried under a forum:
* Uninstall BioShock Retail
* Install BioShock Demo
* Uninstall BioShock Demo
* Install BioShock Retail
All's good now.
It's really perplexing since I did a full Windows Install after I first installed, so no traces of the BioShock demo would be there...