[debian] zhone not working

[arne anka]

> it seems that xfwm4 doesn't start automatically

yes, i suspected something like that.

> someone knows where xfwm should be called?

normally, it should be started by startxfce4 as well.
at a glance, there are several files startxfce checks for informations --  
so either you could start xfwm once from within xfce and see, if it is  
started automatically afterwards or you need to do some deeper debugging.
comment the startxfce4 line in ~/.xsession and restart X, then start  
startxfce4 via ssh and have a look at the output -- maybe something  
helpful turns up.