Disable shared memory usage for Skype. This can prevent http://askubuntu.com/questions/692825/how-to-fix-graphical-issues-with-skype-gdk-warning
--- a/.fvwm/config Fri Nov 27 23:12:46 2015 +0200
+++ b/.fvwm/config Tue Dec 01 22:43:46 2015 +0200
@@ -449,7 +449,7 @@
+ &Emacs%emacs.png% Exec exec emacs
+ &Firefox%iceweasel.png% Exec exec firefox
+ &VLC%vlc.png% Exec exec vlc
-+ &Skype%skype.png% Exec exec skype
++ &Skype%skype.png% Exec exec env QT_X11_NO_MITSHM=1 skype
+ &Goldendict%goldendict.png% Exec exec goldendict
+ xkill Exec exec xkill