is@NetBSD.org said:
>   track (ctl=7) at sector 0 

So it didn't recognize an ISO filesystem on the first session.

>  a:  67108264         0    ISO9660   41354             # (Cyl.      0 - 671082+)
>  d:  67108264         0    ISO9660       0             # (Cyl.      0 - 671082+)

Did you also try to mount /dev/cdXd?

If that succeeded, then mscdlabel is overly picky appearently.
I might have a look at it if you don't mind to send me an image
of the first track (the first 100 blocks = 200k should be
sufficient).

If that didn't succeed, then the CD is somwhow special...
it isn't a Kodak PhotoCD by any chance?

best regards
Matthias