Soundcard unavailable after rendering

[m@RV]

Just doing some mixing and mastering and each time I render a file (export) on completing the CPU meter reads zero, the line is red and there is no sound. If I try to open a different audio driver I get an access error. I can open other audio apps and the soundcard is working fine. The only way to get FLS working again is to close down and reopen (painful)

1) Does this happen to anyone else?
2) Any clues on how to fix it.

Win XP home
MAudio Audiophile card
3 GHz Pentium single core
1 Gig RAM.

[vic]

It's a little odd, as the sound drivers aren't ...