Mike,
The issue is that the XGLite plugin switches from drums to a melodic instrument on the drums channel (10).

This happens if any bank change is sent on the drum channel.
Styles typically send bank 0 on all used channels to insure the correct patch is chosen.

Do you know why XGLite does that?

We previously put an option to never send drum bank changes (on channel 10) to fix the same issue with hardware XG.

So we can have the same option apply to plugins, and that would fix it, but it seems incorrect behavior for a GM synth plugin to not play drums on channel 10 if it has received a bank change event of 0, which is the default bank. The next patch release will have that, and should work for the XGLite (32 bit plugin). As long as Prefs-MIDI Options-Drum Bank Changes is "disabled" (the default is "disabled") . And Prefs-MIDI Channels- Drums should have banks set to 0, though this likely doesn't matter.

Have Fun!
Peter Gannon
PG Music Inc.