The rebuilder works as you think it works. It takes a sourcefile, looks at its checksum and size and if it finds a match with one (or more) of the roms in the datfile, it'll use that found set and romname and creates it in the destination.

Your reported problems sound weird. Maybe you're scanning not the rebuilt roms, maybe you're using a different datfile for scanning, maybe you have dupes spread over the rompaths and cmpro scans only the old and not rebuilt ones.
Maybe you have random checksum errors (see the posting below about a user who gets random checksum errors due to hardware problems).
Maybe a more detailed example would help me to track down your problems.


Another problem could be if you're not using 'recompress'. Direct copying the compressed data is fast, but it won't check if the compressed data is ok. So if your scan shows checksumerrors on a sha1 or a full zipintegrity test while you rebuilt your files with 'recompress' disabled, your zipfiles had errors before.

Roman Scherzer
ClrMamePro