(very) annoying gnome-session behaviour

[Philippe Moutarlier <philippe enit fr>]

Onve before I used gnome-session, then stopped and forgot why ...

Now I remember, and it doesn't look like it is getting better : in some cases (realaudio player for 
example), gnome session prevents some applications menu to work. The menus popup but the mouse is
unable to select on them. The weird thing is : this is not due to gtk/gnome or the window manager. 
If I start the panel manually, there is no pb. 

But now , I have another pb : I cannot log out of the panel if I start it manually . 

What's wrong ?

Philippe