http://bugs.winehq.org/show_bug.cgi?id=26233
--- Comment #8 from Maarten Lankhorst m.b.lankhorst@gmail.com 2011-02-28 22:55:31 CST --- oh... dsound doesn't officially support 5.1 atm, there's a hack in that will allow 5.1 downsampling as long as the frequency/bpp of the 5.1 channel and primary are the same, maybe that would explain something?