Overture crashing near the end of the game, once final chapter loads

[jbone]

I use the crowbar to enter the light-emitting door at the end of the incinerator section. I see the intro text to the next chapter. As soon as the loading's done, instead of seeing the green "click to continue" text, I crash to the desktop.

Here is the error I receive:
"penumbra.exe caused an exception_access_violation in module penumbra.exe at 0023:0058C050"

I've attached a screenshot of the error dialog, including the Stack Trace.

I'm running the Steam version of Penumbra: Overture. Here's my system configuration:

Intel Core i7 860 @ 2.80GHz
4GB DDR3 RAM, dual-channel
Nvidia GeForce GTS 250 1GB, driver version 195.62 released 11/26/09
MSI P55-GD80 motherboard with Intel P55 north bridge and latest BIOS
onboard Realtek ALC889 audio and Realtek 8111DL LAN
Intel SSDSA2M080G2GC boot drive
Western Digital Caviar Black WD1001FALS storage drive (where game is installed)
Win7 64-bit with all latest patches

Thanks in advance if anyone can help. I hate that I've gone through almost the whole game, and now can't finish it...