Right googled about abit and it turns out this is a pretty common problem.
Can be related to the GFX card, but most of us here are using the same one, so thats not likely to be the issue.
Turns out there are quite a few problems with the sound system on the game.
Its recomended that you update all your drivers ect. but like i said the newst (feb 05) driver for the audigy NX seems to conflict with something, possibly dell quickset, and crashes my computer all the time so i dont use it.
However when i turned my external sound card off it stil didnt work.
The fix for me was to delete a openal32.dll file in c:\windows\system32.
The game now works, i've not restarted and i dont know what effect deleteing this file has so do it at your own risk. I didnt delete mine (yet) just moved it to desktop for now.
I'll update this if anything else changes.