First off, I'd like to say I love this sight and I have bought John's book. I'm sure they will both serve me very well when I decide to build my own MAME cabinet.
Here's my problem. I'm having trouble playing only a certain few of my rom's (IE Pac-Man, Moon Patrol, and a few others). Moon Patrol plays fine using Mame32-061, but when I try to use the latest version of MAME32 I get an error stating: "mpc-4a.2a NOT FOUND".
Also, when I try to play PacMan(Midway) using Mame32-061, I receive a missing file error: pacman.5e,pacman.5f, 82s123.7f, 82s126.4a, 82s126.1m, 82s126.3m are all NOT FOUND. In MAME32 v0.102, it won't even list any of my PacMan versions. This is particularly confusing to me because this game played just fine a few days ago.
Furthermore, I can play Galaga(Namco) fine on Mame32v102 but not on Mame32-061, which is just the opposite as I stated above for PacMan and Moon Patrol. And again, files are NOT FOUND.
I've also tried running these ROM's using Mamewah v161 and then using the command line version of MAME0103b. Galaga works like a charm but PacMan and Moon Patrol will not load. The mamewah.log does not state any errors in particular.
I even tried copying all of the roms to each emulator rom directory and that hasn't helped. Am I overlooking something?

Thanks