I've been using Vegas Pro since v4, this is a new first for me. I'm stuck in the middle of an 18 track recording with all FX turned off. Not sure why this just started happening...sometimes as soon as i hit play, other times after 5 minutes or so, and sometimes WHILE i am recording (Grrrrr!). I get the "Unmanaged Exception (0xc0000005)" error. I am not doing ANY video at all, only multi-track audio. Yet i've tried all of the gfx card tricks (Which is the only thing i can find online). All gfx drivers have been updated, as well as audio drivers. Cache has been cleared. PLEASE, any help i can get is truly appreciated. It was working perfect until about a week ago this started happening.

My rig = Win7 Ult N (64), 2x nVidia 550 TI's (SLI), AMD 8120 (3.1 GHz), 16gb Ram

I/O device = Mackie ProFX8 USB Mixer (uses default drivers)

Problem Description
   Application Name:    Vegas Pro
   Application Version: Version 10.0c (Build 470) 64-bit
   Problem:             Unmanaged Exception (0xc0000005)
   Fault Module:        D:\SONY VEGAS\vegas100.exe
   Fault Address:       0x00000001403C8BA4
   Fault Offset:        0x00000000003C8BA4

Fault Process Details
   Process Path:        D:\SONY VEGAS\vegas100.exe
   Process Version:     Version 10.0c (Build 470) 64-bit
   Process Description: Vegas Pro

Problem signature:
  Problem Event Name:    APPCRASH
  Application Name:    vegas100.exe
  Application Version:    10.0.0.470
  Application Timestamp:    4d18eee3
  Fault Module Name:    StackHash_22a1
  Fault Module Version:    6.1.7601.24384
  Fault Module Timestamp:    5c6e245d
  Exception Code:    c0000374
  Exception Offset:    00000000000bf302
  OS Version:    6.1.7601.2.1.0.256.28
  Locale ID:    1033
  Additional Information 1:    22a1
  Additional Information 2:    22a156d8c8cc3aa6c306880cb979afb2
  Additional Information 3:    5391
  Additional Information 4:    53917f189a8755aecaf383fbeaaf7f98