As it seems I'm the only one with this issue, I assume this comes from the graphical card I'm using, wich is not well managed by nouveau driver: I have other problems with it I should report. Moreover, I tried again to reproduce this issue after your answer, but it appears that it works directly sometimes.
I don't want to continue bothering about this until my graphical card works properly. Feel free to close this bug. Thanks anyway, Yvan -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1369719 Title: xfce4-display-settings -m : Need to set "extended desktop" first to be able to select "mirror screens" To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xfce4-settings/+bug/1369719/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
