First a comment. No one seems to offer classes or manuals on Ubuntu so I'll take it that you are seeking Linux or Ubuntu guides. Try http://ubuntuguide.org/wiki/Ubuntu:Jaunty
Since 8.04 is outdated I'd upgrade that.
So here's the drill. My old Ubuntu does that same thing. If I stick a BLANK CDR in there I have to run K3b to burn a data CDR and after that it recognizes that CDR fine.
I have a dell inspiron 910 mini with ubuntu 8.04 pre-installed.
I am trying to connect up my external drive via usb2.0.
I can install the driver disc that came with the unit and an icon appears.However as soon as I remove the disc from the drive the icon disappears and any other cd is not recognised.I know that the system works because I installed it on my dell 510 laptop via the usb connection and it worked perfectly.any ideas