Dead Space Freezes In Ch. 3- help please?!

Hi. I'm on the part right after you activate the centrifuge. I go into a vacuum right outside the store, and jump a couple times. as soon as I get close to the other side, it freezes. sometimes I land, sometimes I don't, I tried underclocking my card, AND turning down the graphics to minimum- nothing works. Here's what the error report says:


Product
Dead Space.exe

Problem
Stopped working

Date
11/11/2008 10:23 AM

Status
Report Sent

Problem signature
Problem Event Name: APPCRASH
Application Name: Dead Space.exe
Application Version: 1.0.0.222
Application Timestamp: 48da0532
Fault Module Name: Dead Space.exe
Fault Module Version: 1.0.0.222
Fault Module Timestamp: 48da0532
Exception Code: c0000005
Exception Offset: 0034cd14
OS Version: 6.0.6001.2.1.0.256.1
Locale ID: 1033
Additional Information 1: e17d
Additional Information 2: 3be9f8a50bddd4313bd572f57066c49b
Additional Information 3: 81dc
Additional Information 4: aa162d78020c3d2d8202ca7dabeada06

Extra information about the problem
Bucket ID: 978835769



My system specs:

ASUS A8N-SLI w/ nForce 4 SLI Chipset, and Realtek ALC850 Audio
AMD Athlon 64 X2 3200 2.2Ghz
HIS ATI 3670 (non-overclocked)
Seagate 300GB SATA II HDD
Linksys Wireless-N Adapter
Plextor 716A DVD-Burner

hopefully someone can help me out. But if not, would it be too much trouble to ask for someone to send a beginning Chapter 4 save on Medium difficulty so I can keep playing?? I really like the game and would like to finish it.