ALT key doesn't work as before

["Manu Hack" <manuhack@gmail.com>]

Now I'm using KDE 3.5.5 on etch. Before my ALT key works as to I can
go to the menu when I press alt. But now, I can only go to the menu in
KDE application. For firefox, gvim, etc. it doesn't work. The main
problem is that it blocks my alt key mapping in gvim. I have checked
kcontrol and alter some options but none of them could fix it. Hope
someone could give me a hand. Thanks.