Could not download from repository problem updating

I'm again not sure what to do here, the following update manager error message received after general system update....

"Failed to fetch cdrom://Ubuntu 9.10 _Karmic Koala_ - Release i386 (20091028.2)/dists/karmic/main/binary-i386/Packages.gz Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs
Failed to fetch cdrom://Ubuntu 9.10 _Karmic Koala_ - Release i386 (20091028.2)/dists/karmic/restricted/binary-i386/Packages.gz Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs
Some index files failed to download, they have been ignored, or old ones used instead."

I've tried to update several times over the last few days.... Before that the updates were installing OK.

Is there a solution to this one.???.. Ubuntu 9.10 installed from supplied DVD in Ubuntu User Mag.... I'm a new to Ubuntu.
Regards... Dave