> So when I hit player 1 and player 2 start buttons SIMULTANEOUSLY > > (which both do keyboard strokes 1 and 2) > > MAME crashes sometimes. Not sure why this would happen... any ideas?
Have a look at the Default Key code table on the page I linked to before. P1 Start is used as a Shift Key. When pressed together with the P2 Start button it sends the esc character to the computer.