Bbutler,
If you are having problems with ANY HPUX specific questions. There is a very good HP website
www.itrc.hp.com
That is their forum for HPUX questions. Although Perderabo has done a good job in diagnosing your problem.
There is another command that you should try "pfs_mount". Do a man on it.
I have had to use this with some Vendor CDs namely EMC cdroms. For some reason, some CDs are created with alternate formats that pfs_mount can read.
Try this and get back to me.
Here is some of the man page.
root> man pfs_mount
Block Cache
This cache holds raw 8k blocks of recently accessed data.
EXAMPLES
To mount a CD-ROM disk:
pfs_mount /dev/rdsk/c0t6d0 /cd-rom
To mount a remote file system:
pfs_mount serv:/cd-rom /cd-rom
To fake an entry for iso9660 on /cd-rom:
pfs_mount -f -t iso9660 /dev/rdsk/c0t6d0 /cd-rom
To hard mount a remote file system:
pfs_mount -o hard serv:/cd-rom /cd-rom