syslog seems to suggest that the x crash really was related to the update-manager problem, I attached the messages from a few minutes before the crash up to the last message before the next boot.
In particular, this message appears at the same time the X server disappeared: AptDaemon.Worker: CRITICAL: Killing child since timeout of 600 s ** Attachment added: "syslog-excerpt" http://launchpadlibrarian.net/33603516/syslog-excerpt ** Attachment removed: "syslog-excerpt" http://launchpadlibrarian.net/33603516/syslog-excerpt -- module rt2860sta ERROR!!! RTMPCancelTimer failed, Timer hasn't been initialize! https://bugs.launchpad.net/bugs/376577 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs