Um, I've got a WDM driver for my soundcard, with full-duplex, and my Mugen game has full stereo and no sound pitch retardation. MP3 playback tends to sound kinda horrid, particularly with low-volume MP3s, but characters' sounds usually sound just fine. Only problem is that the sound in Mugen tends to completely stop working until reboot if I exit Mugen and then run it again.
Too lazy to try Tom Servo's trick, though.
Still quite busy.
(Yes, I intend to deal with that stuff eventually, but kinda can't just yet, sorry. :/ )