Anyone else find that pressing the ‘B’ button in LR-MAME on v32 causes both A and B buttons to be pressed simultaneously? To test, try Final Fight - you’ll be constantly doing roundhouses. Similar with Cadillacs & Dinosaurs, 1944, Robocop etc.
Can’t see any obvious reason why this should be the case. Standalone MAME works OK. MAME2003+ seems OK too.