This command allows you to load a ASCII 8K type Megarom file into a same type
MegaFlashRom. In addition, the Roms or Megaroms files are converted on-the-fly
to fit them to be used with the same MegaFlashRom type. Some ROMs are also
patched to correct the known problems. (See Converted Roms List)
The tool to use would be FL8.COM in your case.
It's weird that your cartridge has issues with some mapper and not others... You can also give SofaROM a try (puting your cartridge in Konami/SCC mode). Maybe it can make a difference, at least if the problem is related to the flash software and not the hardware on your cartridge (I do not believe in it but who knows?).