It's likely you need at least 1 new V ROM chip. Got the same problem on my King of Monsters 2 at the moment. I thought it could have been the PCM chip but i've swapped that from a Super Sidekicks 2 board already and both games are the same, so it wasn't the PCM chip. I've also dumped and checked the M1 chip and that's also fine in my case.
9 times out of 10 if cleaning doesnt work you need a new V ROM chip.
See this thread:-
http://www.neo-geo.com/forums/showthread.php?247810-42-pin-EPROMs
It has a link to a chinese company which i've used before. You can order some EPROMs from there, and email the V ROM images from a working emulator version. If you can somehow work out which V ROM chip it is then obviously that's the best way so you only need to order one chip.
They are reasonably priced anyway, I paid something like $15 (shipped) for a 2Mb 27C160 and a 1Mb 27C800 with the 2 V ROM images pre-programmed by them.
Alternatively get something like a Willems programmer, desolder the chips and read them - compare checksums against emulator copies and replace chip(s) with EPROMS as required.
