I have done a retest with the original reproducing steps. The crash is still there and now identified by apport as xorg server crash, which is reported here:
https://bugs.launchpad.net/ubuntu/+source/xorg-server/+bug/1044680 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1001711 Title: bzr-explorer makes the system unusable after clicking the customization button To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/bzr-explorer/+bug/1001711/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs