Problems with menus in Amarok 2 and KDE 4

[Enzo Cappa <zcappa@gmail.com>]

When I'm playing a track in Amarok, I can't use any menu, because it just closes immediately after it opens. If no track is playing, all menues work normally. 
I'm using KDE 4.2.1 and Amarok 4.2.1 installed from experimental and unstable. 
Thanks!