MPF uses hashes, not the disc name to compare against dumped discs in the db. If you have the option enabled to display the submission info form and some fields are filled in the disc has already been dumped.
Ah, so if I have an account and put my login info into the Options -> Login Info, it automatically checks the DB upon ripping.
When having ripped discs before without login, I guess, it doesn't count anymore. Or could I just put in the same disc again if I haven't moved the ripped files so far?
If I'm understanding you correctly it's scanning .cab files and the like. There's virtually no reason to do this that I'm aware of and there's an option to disable it.
Hm the only option I can find about it is the Protection Scan. Looking at your next answer, I would say, I could disable it and just use Protection ID afterwards.
If using MPF on a CD, in the end I will have 3 image files of the whole disc, where 2 are bit-identical. For storing them on my NAS, should I safe all of them?
As I just bought a PX-W4012TA for CDs, and using the ASUS BW-16D1HT for DVDs, I would like to contribute, being a perfectionist I'd want to have most accurate rips of my discs.