Thanks for the reply. By Other Themes, I mean within AM, using Attrac-Man for example, everything works and games launch. When I switch to Nevato or Robospin (the themes with wheels) - the games won't launch - just a flicker, pixelation for a moment, then back to the them as if I exited out.
When I run in console mode, no errors appear, in fact is says "***Running". I thought maybe it was launching on another phantom screen, but I have multi-screen disabled, and no other monitors set up.
Really stumped, what could go wrong at the handoff from AM to MAME in Nevato/Robospin only?