There seems to be quite a general ACPI / Xorg problem with recent Edgy updates. The ACPI=off kernel boot option at least allowed me to start X after booting.
-- Oops (xorg) after dapper->edgy dist-upgrade Toshiba Portege 4000 https://launchpad.net/bugs/64081 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs