Amnesia stutters ever 1-2 seconds

[bbarker831]

For several months while playing, the game ran smooth as butter with most of the settings on HIGH, but a month went by without playing and when I came back, the frame-rate stuttered at 1-2 second intervals, and I lowered settings, didn't work. Lowered SSAO, resolution, etc. and it still didn't work. I then updated Nvidia drivers and still, same problem. I've tried everything (even uninstalling from steam) and the problem is still there! What's the deal?

Windows 7 Pro
Processor: Pentium D CPU 2.80GHz, 2793 Mhz,Dual Core
RAM: 4GB
Nvidia GeForce 7800 GTX 256 MB

Attached is my hpl.log