Bug playing game second time around (xrayengine bug)

I played the game the whole way through the first time and had no bugs.

The second time I had no issues until I had gotten to the Pripyat section. I actually went mostly through it and left to get more med kits/bandages.

When I returned the game began to crash. I tried going back a bit and starting the game a bit before Pripyat but seemed to have issues when I finally got to Pripyat.

The error says:

Xrayengine_error_report_
080913-031328.zip

Any ideas? I downloaded the latest three official patches and other then some second delays when the graphics were on the high end, well, as I said, no problems the first time playing it through.

Here are the stats for my computer and it's Vista, business edition:

Best,

Bishop

Operating System: Windows Vista Business (6.0, Build 6000) (6000.vista_gdr.071009-1548)
Language: English (Regional Setting: English)
System Manufacturer: Dell Inc.
System Model: Dell DXC061
BIOS: Phoenix ROM BIOS PLUS Version 1.10 2.3.2
Processor: Intel(R) Core(TM)2 CPU 6300 @ 1.86GHz (2 CPUs), ~1.9GHz
Memory: 2046MB RAM
Page File: 1942MB used, 2365MB available
Windows Dir: C:\Windows
DirectX Version: DirectX 10
DX Setup Parameters: Not found
DxDiag Version: 6.00.6000.16386 32bit Unicode

---------------
Display Devices
---------------
Card name: 256MB ATI Radeon X1300PRO
Manufacturer: ATI Technologies Inc.
Chip type: Radeon X1300/X1550 Series (0x7183)
DAC type: Internal DAC(400MHz)
Device Key: Enum\PCI\VEN_1002&DEV_7183&SUBSYS_0D021028&REV_00
Display Memory: 1018 MB
Dedicated Memory: 255 MB
Shared Memory: 763 MB
Current Mode: 1024 x 768 (32 bit) (75Hz)
Monitor: Generic PnP Monitor