The default window manager started by the DM for old users also changed in Simply Linux 7.0.x (from Xfce4) after I apt-get-installed mate-document-viewer (and hence mate-session). lightdm and /usr/bin/runwm are involved in starting the DE/WM. A solution for this problem would be to write "Xfce4" into /etc/sysconfig/desktop in Simply Linux installations, right? +++ This bug was initially created as a clone of Bug #26112 +++ gdm2.20-2.20.8-alt6 In Simply Linux beta 2011-08-11, where there was only Xfce and it was the default desktop env and window manager, I've apt-get-installed WindowMaker-0.94.0-alt2 and xmonad-0.9.2-alt2 additionally. After that, the "default" session in gdm started to call xmonad, even for those users who previously used Xfce (as the former "default"). This is a trouble for the administrator that installing additional window managers changes the meaning of the "default" option. The installation of additional window managers shouldn't change the default.
Fixed in Simply Linux 7.0.5 RC1