Hi
i just found a work-around for the moment.
it seems that it wants the properties TryExec and URL set for the menu items (in addition to just Exec).
adding a new item does not set these extra properties.
a recent post noted that aparrently it is a gnome-panel bug that has just been fixed.
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=291185
http://bugzilla.gnome.org/show_bug.cgi?id=165799
just waiting for the package to make its way through to the debian list from gnome cvs.
thanks for your responses.
Takis