I've tried the +W switch. I found it in the readme after posting my original message. Anyway, it stopped the dropping of frames in the video, but sound still cuts out for maybe 1 second out of every 10. This is up from maybe 1 out of every 5, plus the Video choppiness before. Since this morning I've also -Upgraded to DirectX9.0A -Upgraded to the March Detonators 43.45 I think I'll attack the sound card angle now. New drivers, tweaking acceleration etc. I have an Audigy and I hear they do cause problems sometimes, so here's hoping.