In the Software Centre, under Installed Software, I have a number of packages marked as coming form "other". Where might these have come from? The
libdvdcss2 entry does not surprise me, but I have no idea where the qt and update-manager entries have come from.
As far as I'm aware I have never installed these packages from a PPA, or installed them manually.
Update: After taking the screenshot I removed the qt packages because I don't actually need them. However the output of
$ apt-cache policy update-manager is:
update-manager: Installed: 1:0.142.21 Candidate: 1:0.142.21 Version table: *** 1:0.142.21 0 100 /var/lib/dpkg/status 1:0.142.20 0 500 http://gb.archive.ubuntu.com/ubuntu/ maverick-updates/main i386 Packages 1:0.142.19 0 500 http://gb.archive.ubuntu.com/ubuntu/ maverick/main i386 Packages
I'm wondering if it could be to do with the maverick-proposed repository.