More possibilities to try Disable xorg.conf (Squeeze doesn't normally need it) mv /etc/X11/xorg.conf /etc/X11/xorg.conf.renamed apt-get update apt-get -f install dpkg-reconfigure xserver-xorg If you use a proprietary graphics driver, have you reinstalled it? "KDE-Trinity 3.5.13 hung my machine" might not be quite correct, maybe more to do with a xorg/graphics related issue in the Debian upgrade