Demo crashes on startup - Error locking VB

Just got the demo and when I launch it I hear the music but no video. Then after a second it gives me an Error locking VB demo.

My specs are Windows Vista 32, Core 2 Duo E8400 (3Ghz not OC’d), GeForce 9800 GT, 2 GB RAM.

And the debug file

Help me please :cry: