I have no idea. If all you did is replace MAME 0.193 with MAME 0.194 (official Windows builds) it must be related to some changes in the last MAME version... probably a MAME-dev can shed some light on it?
A mind is like a parachute. It doesn't work unless it's open. [Frank Zappa]
We're searching for QMC2 translators and support for existing translations. Interested? See here!
One other question - If I set the Machine List view to 'Hierarchical View' is it normal behavior for QMC2 to revert back to 'Full Detail View' upon exiting program and starting back up? Hierarchical View setting doesn't stick.