i'm playing around with the vegas 5 trial and it has crashed several times while previewing clips in the media pool. here is my trace.

Sony Vegas 5.0 TRIAL
Version 5.0a (Build 134)
Exception 0xC0000005 (access violation) WRITE:0x494A3DC IP:0x1F9E357
In Module 'aviplug.dll' at Address 0x1F60000 + 0x3E357
Thread: VideoRender ID=0xAA0 Stack=0x52DF000-0x52E0000
Registers:
EAX=000073fb CS=001b EIP=01f9e357 EFLGS=00010202
EBX=00001556 SS=0023 ESP=052df820 EBP=052df838
ECX=02028098 DS=0023 ESI=04915030 FS=0038
EDX=02027cc0 ES=0023 EDI=04910404 GS=0000
Bytes at CS:EIP:
01F9E357: 0F 7E 0C C7 8D 4C 99 04 .~...L..
01F9E35F: 83 C6 08 81 FB 56 15 00 .....V..
Stack Dump:
052DF820: 00000001
052DF824: 02027CA0 01F60000 + C7CA0 (aviplug.dll)
052DF828: 04911EF4 04910000 + 1EF4
052DF82C: 04911EE0 04910000 + 1EE0
052DF830: 0201E2B0 01F60000 + BE2B0 (aviplug.dll)
052DF834: 00000000
052DF838: 04910000 04910000 + 0
052DF83C: 01F9869D 01F60000 + 3869D (aviplug.dll)
052DF840: 04911ED8 04910000 + 1ED8
052DF844: 04910000 04910000 + 0
052DF848: 038D8598 03710000 + 1C8598
052DF84C: 02ADD170 02A20000 + BD170
052DF850: 052DF928 051E0000 + FF928
052DF854: 00000000
052DF858: 0201DE44 01F60000 + BDE44 (aviplug.dll)
052DF85C: 04910400 04910000 + 400
> 052DF8B8: 01F847C0 01F60000 + 247C0 (aviplug.dll)
052DF8BC: 04910000 04910000 + 0
052DF8C0: 00000003
052DF8C4: 0A9317B8 0A920000 + 117B8
052DF8C8: FFFFF4C0
> 052DF8D8: 01F7860D 01F60000 + 1860D (aviplug.dll)
- - -
052DFFF0: 00000000
052DFFF4: 00569450 00400000 + 169450 (vegas50.exe)
052DFFF8: 0388E8E0 03710000 + 17E8E0
052DFFFC: 00000000