Need help with NeoCD

Ok, everything on my neocd seems to be working fine except for a few games. Aero Fighters 3, Metal Slug, and Metal Slug 2 are all missing background music. The sound effects are fine. Puzzle Bobble is the only one thats working perfectly. Does anyone know why this is? In short, music is turned on. Sound is turned on. Only sound effects are working. Stupid music won't work. :D. This happened when I updated my neocd to the latest patched one (5.3), and didnt the guy say he fixed the problem with Aero Fighters? Oh well. Please help. :D

i've never tried neocd, but since it works in other games without changing setting, it seems ok to assume it's a bug/problem with the emulator. someone correct me if i'm wrong

My Metal Slug has the music but not Mslug2 just the sfx. I just took out the mp3s to save on room now.

Aero Fighters 2, Aero Fighters 3 and Metal Slug 2 are working fine. Sound FX and Background Music 100%. The only thing with Metal Slug 2 is that is it runs a bit slow, but playable. I know you probably know this but be sure there is a "neocd.mp3" folder within each game folder and the mp3's go in there.

Aero Fighters 2 - 33 tracks/61.0 MB
Aero Fighters 3 - 26 tracks/37.3 MB
Metal Slug 2 - 19 tracks/56.8 MB

I can't seem to run Aerofighters 2 & 3, Metal Slug, or King of Fighters '99 on my v0.5.3. I get an error message that says 'Failed Allocating PRG memory'. I left them zipped, am i doing something wrong or did I just d/l bad files from a particular site?