Comment 8 for bug 915235

A fix as been proposed in a french ubuntu forum : http://forum.ubuntu-fr.org/viewtopic.php?id=790301
it worked for me.
launch muon
in configuration, source configuration
check everything exept cd-rom in the 'other software' tab
in the 'update' tab, check 'suggested update' (the only one uncheck by default)

I work in a french version of ubuntu so i hope the translation is good enough