Apparently the problem was the nvidia driver. When I upgraded xorg I upgraded the nvidia driver to the last beta version too. The bug is not reproducible with vesa, so I'm going go puke the nvidia guys =).
Thanks for your help, this bug is solved for me -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
