I see that running MAME ROMs is problematic (e.g. here). I am in the same boat. Even the ROMs that are listed as supported exhibit the same problem.
I am running a from-source build that completed just yesterday, so it’s basically the most up to date available. I have tried replacing %ROM% with %BASENAME%. I have tried all the commented out COMMANDs (i.e. alternate emulators) in the MAME system configuration.
Can anyone enlighten me as to whether this should be working? What might I be doing wrong?