Thanks for the guide!

I've tried to add a parameter to the osso-xterm, but it seemed not to work. For anyone else facing this issue, delete this line from the osso-xterm.desktop file:

X-Osso-Service=xterm

The wiki article describes what was going on there:

X-Osso-Service (string, DBus service name) - if specified hildon desktop will try to call the top_application method on this service rather than execute what is listed in the Exec field).