Please attach your /var/log/Xorg.0.log and the output of 'lspci -vvnn'. Also, try disabling compiz (such as via chmod a-x /usr/bin/compiz) and see if that makes it start up properly.
Please attach your /var/log/Xorg.0.log and the output of 'lspci -vvnn'. Also, try disabling compiz (such as via chmod a-x /usr/bin/compiz) and see if that makes it start up properly.