Updating keep giving error message

[Mark]

When ever I check for new updates I receive the following message:

W:GPG error: http://ppa.launchpad.net oneiric Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 7D2C7A23BF810CD5, W:Failed to fetch http://ppa.launchpad.net/dockbar-main/ppa/ubuntu/dists/oneiric/main/source/Sources 404 Not Found, W:Failed to fetch http://ppa.launchpad.net/dockbar-main/ppa/ubuntu/dists/oneiric/main/binary-i386/Packages 404 Not Found , E:Some index files failed to download. They have been ignored, or old ones used instead.

[Ubuntu Foundations Team Bug Bot (crichton)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. It seems that your bug report is not filed about a specific source package though, rather it is just filed against Ubuntu in general. It is important that bug reports be filed about source packages so that people interested in the package can find the bugs about it. You can find some hints about determining what package your bug might be about at https://wiki.ubuntu.com/Bugs/FindRightPackage. You might also ask for help in the #ubuntu-bugs irc channel on Freenode.

To change the source package that this bug is filed about visit https://bugs.launchpad.net/ubuntu/+bug/897754/+editstatus and add the package name in the text box next to the word Package.

[This is an automated message. I apologize if it reached you inappropriately; please just reply to this message indicating so.]

[Mark (hmostashari)]

the source package is oneiric (11.10)

[Vadim Rutkovsky (roignac)]

Dockbar should have Oneiric builds in PPA