Amneisa constantly crashes during play

[Inkling]

Amnesia always crashes within 5 minutes of starting play, usually when I am turning to look at something. The image freezes for several seconds (I can see the motion blur effect) , then there's a a brief flash of a repeating white diamond pattern on black, then the screen goes white and stays that way until I tell Windows to close the program.

Playing via Steam on Win 7 64 bit with a Radeon HD 4870. Steps I've taken to solve to troubleshoot so far:

-Updated GPU drivers to the latest
-Confirmed that my GPU supports OpenGL 2.1+
-Verified the "integrity of the game cache"
-Delete configuration file and user profile
-Restart the computer
-Disable Steam overlay
-Run gamewith no other programs running
-Disable AVG anti-virus
-Revert to auto-detect settings
-Disabled SSAO
-Currently experimenting with reducing settings.
-Next step will be to re-install the game.

How do I stop the crashes?


Thanks!