"Are you trying to change from a Hi-Q MIDI patch to another Hi-Q MIDI patch? If so, you should be able to do that"

Yes, that's almost always what I am trying to do. And indeed that's what I was trying to do this last time, just yesterday, when (rather predictably) it got "stuck". Thanks for the knowledge though, never hurts to learn exactly what's going on.

Yes, I'm putting it down as a bona fide bug and will probably follow through on that wish list suggestion, thanks!