xfwm4 has fixed this upstream. see http://bugzilla.xfce.org/show_bug.cgi?id=4434#c8 Yves-Alexis Perez did include patches in xfwm4_4.4.2-6_i386.deb, see http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=483070#56