Sorry, for the follow-up, but I doubt that it is a bug in patin couffin.
As I am using DVD Decrypter with patin couffin as the standard I/O interface as well, I gave DVD Decrypter 188.8.131.52 a try and the volume label of a SecuROM protected DVD (same one as above - "Pro Evolution Soccer 3" to be more precisely... Pro Evolution Soccer 4 and Half-LifeÂ² do have the same problem) was detected and read out correctly.
So, I guess it must be something else, but what could it be?
Edit: Oh I see, BW says that the size of this disc is only 2.48 GB, but it should be roundabout 2.86 GB...