Hi bernie,
Thanks for those tips, renamers will have check the dats/images so it may take some time before it gets fixed but the info is highly appreciated

After a brief look at some dats of the dats i can see that some files are indeed duplicated (crc/md5), we've tried to fix cases where that happened before but mostly inside the same dats/systems i think. Sets with various roms are a bit more complex as you know since some dupes could be false positives, like a readme file or an image that is indeed similar between 2 sets. Anyway that should be checked and thanks again for the info.
If you have anything more to help us out feel free to do so
