> I just got my Raspberry Pi Mame cabinet up and running for a test before I gut it for > painting.
There's your problem. If you have an RPi, you are NOT running MAME. You are running some simalcrum that started with 1999-era MAME and they've since rewritten enough of it to count as a completely new work (and technically be in violation of the license for trying to claim it's MAME).
MAMEdev is kind of terrified of the number of people who run that catastrophe and assume that real MAME is just as bad.