Hi jforster,
I did a quick look over your set up. You may need to update the motherboard bios.
System Manufacturer: ASUSTeK Computer Inc.
System Model: G73Jh
BIOS: BIOS Date: 10/30/09 15:13:23 Ver: 08.00.10
Check your ATI driver, I think there is a more recent one out:
Driver Model: WDDM 1.1
Driver Attributes: Final Retail
Driver Date/Size: 3/8/2011 22:55:52, 795136 bytes

Your HDD needs cleaning and freeing up more space - defrag it.
Disk & DVD/CD-ROM Drives
------------------------
Drive: C:
Free Space: 134.7 GB
Total Space: 416.0 GB
File System: NTFS
Model: ST9500420AS
I'm concerned you may be experiencing a slow failure of your HDD and the processing of data may be showing the issue up.
1. make sure you free up more GB space.
2. ALL address locations of the media files are short, for example C:\Video\Project.
3. Please Export your project and attempt to render again to a new location.
Export: a) Create a new folder in Video\Project\Test
b) File > Pack Project Materials > browse to the new folder location and all media will be reproduced.
c) Close PD
d) Go to the Video\project location and find the new .pds file, double click it.
e) proceed to render your project.

I would like to see screenshots of the NEW folder - I'm looking for file names and extensions - I want to see all please.

I want to see a screenshot of the edit workspace showing the project in the library and timelines.

I am concerned you have corrupt(able) media content which could be causing the problem.

Dafydd