I switched to GDM as a workaround, which works fine. Seems to be a kdm- specific bug.
** Changed in: kdebase (Ubuntu) Status: Unconfirmed => Confirmed -- KDM fails to launch X on edgy https://launchpad.net/bugs/59242 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs