The Black Plague demo crashes whenever I turn on post-effects. Every other setting could be at full (not the case in this crash), but the game only crashes when post-effects are turned on. In this example, I started a tutorial without post-effects on, then enabled them.
I was able to run post-effects in both Penumbra: Overture and the Penumbra tech demo with no problem.
See most recent post: error occurs with Overture too, probably a driver problem.
UPDATE: This crash occurs in the Penumbra: Overture too! I am using the most up-to-date ATI drivers (8.1), which goes along with some of the other error reports. However, instead of having graphical glitches, I'm experiencing a full crash.
I'll attempt reverting to an older version of the drivers (7.9) to see what happens.