So i found a way to make auto-rotation work:
make a script named rotation in /usr/local/bin with the following text:
#!/bin/bash
while (true) do
sleep 2
chkhinge ]& /dev/null
done
make it executable with: chmod +x /usr/local/bin/rotation
then put this line under the xmonobut& in /usr/local/etc/xfce4/xinitrc
rotation&
I tried to make the thing work as sashz do by catching the Sys_Req keyevent and executing chkhinge, but xfwm4 doesn\'t seem to handle this in default.keys, if someone would like to try ..