black plague keeps crashing?

[torbiditree]

Hi. I recently bought Amnesia and the Penumbra series off of Steam. I've played the demos for all three games in the past and they worked absolutely fine.
I tried to play Black Plague this evening. I started a new game, got past the first cutscene, and everything was fine. However, once I tried to turn on the glowstick the game crashed. I tried to play the game again a few more times but it crashed again and again. It wasn't always because of the glowstick- one time I had just gone into the vent and then it crashed, and another time I was trying to close the Steam menu I had opened and it crashed. I kept getting the same message. It said the following:
"The cause of the crash is probably one of the following:
1. You do not have the latest drivers for your graphics card
2. You do not have the latest drivers for your sound card
3. You have made a setting that your computer does not like. To reset settings, go to Documents/Penumbra/Black Plague/ and delete settings.cfg in the correct episode folder.


Exception Reason
penumbra.exe caused an EXCEPTION_ACCESS_VIOLATION in module penumbra.exe at 001B:00535C4F"


I don't understand what the problem is though. The demo ran just fine, and I can run Amnesia (which i'm pretty certain needed better graphics than penumbra did) just fine, so why won't Black Plague work?

Any and all help greatly appreciated. Thanks.