In my quest to make a ClrMAME install completely 'drive independent', I've found that the backup path needs the drive letter to fully function. It will accept "\" as the start of every path setting within the .cmp file, except when it comes to the backup path. Fully unneeded romsets are able to be backed up, but if just a portion of a it requires backed up, then it needs the full path including drive letter. Is there something obvious I'm missing?