I recently upgraded from 10.04 to 12.04, hoping my dvd drive and usb problems will go away. I inserted dvd (some s/w installation) and it would not show up on the desktop. I then did dmesg | grep sr0 and the last several lines of the output are as follows. There is some error which I dont understand and do not know how to fix. Please help.
[ 3914.233310] sr 4:0:0:0: [sr0] Unhandled sense code
[ 3914.233315] sr 4:0:0:0: [sr0] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE
[ 3914.233321] sr 4:0:0:0: [sr0] Sense Key : Medium Error [current]
[ 3914.233328] sr 4:0:0:0: [sr0] Add. Sense: Unable to recover table-of-contents
[ 3914.233337] sr 4:0:0:0: [sr0] CDB: Read(10): 28 00 00 00 00 00 00 00 01 00
[ 3914.233354] end_request: I/O error, dev sr0, sector 0