Well..there are various ways to test if your dumped rom is ok or not.

- redump it several times and compare the files
- if the system is already emulated, check the game in the emulator
- several systems have a system checks which calculate checksums of the roms
- etc...etc...

Well...if 2 dumps of the same rom exists and they differ you will be able to figure out which may be bad (maybe both are ;)) by comparing them..

Ask guru...bet he knows much more ways of being sure if a rom is ok or not.

Roman Scherzer
ClrMamePro