Ingame VON causes hardlock?

[max power 21]

I've been having trouble playing with VON enabled. It seems that when I try to use it, it causes are really hard crash. At the moment when I or someone else is trying to communicate, the screen flashes and makes this really high pitched saw tooth or square wave form sound, then proceeds to play back what sounds like a portion of some voice communication at a very low rate. That portion of the voice sound is very slow and also at a very low pitch. The screen seems to resize so that there is only a blue box with no print in it in the centre of the screen, that seems to measure about 500x500 pixels, and then the computer hard locks forcing me to hold the power button down to restart it. At restart, windows tells me that it had to recover from a serious error. Once it took me to the selection startup screen and recommended I start in safe mode.

This has happened consistently on VON enabled servers, but not at all on servers with VON disabled.

AMD Athlon 64 X2 4400+ @ 2.5Ghz

Asus A8R32-MVP Deluxe

2GB RAM

2 ATI Radeon X850s 256MB in Crossfire (disabled for ArmA)

Acer AT3201W 1360 x 768

Creative Soundblaster Audigy 2

Windows XP Professional 32-bit

ArmA v1.05 running with eax and hardware accelleration enabled

I should add that VON works fine for a very short period of time and then ArmA goes bananas.