I have upgraded 2 laptops to 13.04. and as usual, the upgrade process disables the third-party repositories. The only problem is that after the upgrade is completed, it is not possible to reeanable these third-party sources (namely here, dropbox and google-music-manager). Trying to thick on these sources is just not possible and editing them neither.
ProblemType: Bug
DistroRelease: Ubuntu 13.04
Package: software-properties-gtk 0.92.17
ProcVersionSignature: Ubuntu 3.8.0-19.29-generic 3.8.8
Uname: Linux 3.8.0-19-generic x86_64
ApportVersion: 2.9.2-0ubuntu8
Architecture: amd64
Date: Sat Apr 27 18:38:35 2013
InstallationDate: Installed on 2013-04-20 (7 days ago)
InstallationMedia: Ubuntu 13.04 "Raring Ringtail" - Alpha amd64 (20130402.1)
MarkForUpload: True
PackageArchitecture: all
SourcePackage: software-properties
UpgradeStatus: No upgrade log present (probably fresh install)
Thank you for taking the time to report this bug and helping to make Ubuntu better. This particular bug has already been reported and is a duplicate of bug 1069019, so it is being marked as such. Please look at the other bug report to see if there is any missing information that you can provide, or to see if there is a workaround for the bug. Additionally, any further discussion regarding the bug should occur in the other report. Feel free to continue to report any other bugs you may find.