It's this one the same as this Dapper bug? For me, to get the partitions on desktop and computer:///, i have to do the /etc/init.d/dbus restart stuff, using up-to-date Dapper.
https://launchpad.net/bugs/32628 -- partitions manually added to fstab do not show in 'Computer' https://launchpad.net/bugs/13985 -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs