On multi-session CD-R disks written in ISO9660/Joliet format
appended sessions are not seen. They are seen in Windows
NT4. Wrting program: CeQuadrat WinOnCD 3.6
I don't know if this is the problem you are running into, but it
appears that some software does not follow the written standard
for such disks.
/usr/src/linux/fs/isofs/inode.c has some defines that can be
changed to deal with non-standard disks; if you are interested
you can play with those.
This is more of a kernel problem
Does this still happen in 2.4? I recall a number of bugs being fixed wrt cdrom
handling and within isofs, so I will assume it is fixed unless reopened.