M-Audio have posted up a newer build Revolution 7.1 Driver for Me, 2000 & XP - Version 5.10.00.0051. So what's changed?
Updated Sensaura Support
Better CPU Utilization
AC-3 Handling Improved
Audio artifacts when starting recording or playback with 24 bit MME mode corrected.
Audio artifacts with test tone start up have been corrected.
Win Amp 2.8 users will no longer experience a problem with audio continuing to play after the application has been exited. Win Amp 3.0 still exhibits this behavior & is scheduled to be resolved in our next driver update.