I have a powerbook 17'' g4. I recently replaced my UJSUPER 846CA /MODELUJ-846-C (PANASONIC=SHIKOKU ELECTRONICS) with a used 845CA MODELUJ845Ce, it accepts dvds, cds etc, but it eject them after 1-2 without mounting desktop. Also no device found in system profiler. Do I need perhaps some of driver???Any help would be greatly appreciated.