Running Lion 10.7.1 on a mid 2007 iMac 7,1 and am having issues with mounting drives other than the start-up. Ext Firewire & USB drived have to be mounted with Disk Utility and interior SuperDrive requires Disk Utility to mount. I notice the optical drive has two entries, Hitachi SW_VCD and Superdrive. A DCD is mounted on the Superdrive only. Once mounted, all read and write OK.