Hi,
Just check whether your volume management daemon(vold) is working or not(using ps command).U can restart the daemon by restarting the
/etc/init.d/volmgt service.
Then eject cdrom and insert again and check whether the system is able to recognise the cd-rom.
Alternatively,u can manually mount the cdrom by giving the command
mount -F hsfs -o ro /dev/dsk/c0t6d0s0 /cdrom
I hope this is helpful to u.