Menu underneath windows un Mandrake 10.1

[Alexandre Aractingi]

Hi all, not sure if it's XFCE-related, but since I switched to Mandrake
10.1 (comes with XFCE 4.0.6) the menus that pop-up from the panel show
up underneath the active windows, not above them. Is there a way to
force them to cover any active window?
(PS: I used to also use 4.0.6 under Mandrake 10.0 and everything was
fine, so I'm not sure it is XFCE-related...)
Thanks!

-- 
Alexandre Aractingi <aaractingi at libertysurf.fr>