Reset all prefs to factory. No change.

Version is BiaB 2011 build 313

I'm using the HD Audio on my MSI motherboard. Not sure what the audio chip is.
The problem occurs with both Coyote Forte and the Coyote WT wrapper.

Real styles are fine but it is affecting all MIDI styles, which are experiencing the exact same timing problems. As if some beats are a little late or early, or all late but to varying degrees. It's the sort of thing you might expect during live playback if you were taxing your system, not during a render when time is free.