I'm not sure what you mean with "kernel call trace". The first entry in syslog which is related to the crash mentioned in #13 is
Nov 1 12:53:06 gondor org.a11y.atspi.Registry[4315]: XIO: fatal IO error 11 (Resource temporarily unavailable) on X server ":0" But this is not always the same. See attached syslog file (#2) for the three events at Oct 28 15:56:36 Oct 28 12:06:58 Oct 28 09:08:51 -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xorg in Ubuntu. https://bugs.launchpad.net/bugs/1510998 Title: Xorg crashes with segfault on 15.10 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1510998/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp