Solution : Remove the "libgl1-mesa-dri" package from Beerorkid repository "deb http://www.beerorkid.com/compiz/ dapper main" which breaks the update.
gksu "upgrade-manager -c -d" should then work. -- update-manager for edgy needs to upgrade dpkg/apt before calculating the upgrade to support the new "breaks" - otherwise the upgrade may fail https://launchpad.net/bugs/54234 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
