I've been going through and dumping all my PC games, and I've noticed that a number of SecuROM protected discs don't end up with hashes matching the ones in the database. For multi-disc games, this often only happens for the SecuROM protected discs. For example, I just dumped Aliens Versus Predator 2, and my Disc 1 (which has SecuROM) has a matching size but not a matching hash when compared with http://redump.org/disc/12832/. Disc 2 (which doesn't have SecuROM) has a matching size and hash. While it's certainly possible it's just a pressing difference (my Disc 1 is manufactured by TECHNICOLOR just like the one in the database, and has the same IFPI number, but some parts of the mastering ring differ), I've seen this with several discs so I wanted to inquire. I know that the current DICUI releases run the ECC checker and it replaces the bad sectors (SecuROM sectors) with dummy data. Is it possible that some entries predate this dummy data replacement, or that maybe some other dummy data was used? Or is this definitely a pressing difference?
My setup: Dumping with DICUI and a Plextor PX-760A. I've tried redumping discs that don't match, and I've always gotten identical hashes between the two dumps. No unintentional C2 errors reported by the drive. When checking hashes, I'm using the "!submissioninfo" file generated by DICUI. I've also hashed with 7-ZIP and got the same thing.
Edit: I think this was a bug with DIC. I updated to the newest release and got a matching hash.