I managed to workaround the trouble : $ sudo rm /usr/bin/thunderbird
The facts are that : - gnome-default-applications-properties looks for mozilla-thunderbird and thunderbird executables and show corresponding entries in the menu ("Mozilla Thunderbird" and "Thunderbird"), - thunderbird package install both /usr/bin/mozilla-thunderbird and /usr/bin/thunderbird links (the target is ../lib/thunderbird/thunderbird for both). Usefull commands to understand the facts : $ strace gnome-default-applications-properties 2>&1 | grep thunderbird $ dpkg --listfiles thunderbird -- After installing Thunderbird, preferred applications shows both "Mozilla Thunderbird" and "Thunderbird" https://bugs.launchpad.net/bugs/373167 You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to nautilus in ubuntu. -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs