While trying to catch a samba related bug, Steve Langasek pointed me to this NM bug. The screenshot shows the "nm-dispatcher.action: Caught signal 15, shutting down..." message.
Steve's comment (https://bugs.launchpad.net/ubuntu/+source/samba/+bug/211631/comments/191): Markus, your screenshot shows a network-manager error: nm-dispatcher.action: Caught signal 15, shutting down... This indicates that some part of NM is not being correctly guarded from /etc/init.d/sendsigs, resulting in abnormal termination that breaks the network connection before network filesystems are being unmounted. Network Manager has previously been fixed for such bugs, but it seems to have recurred. ** Attachment added: "Shutdown messages" https://bugs.launchpad.net/ubuntu/+source/network-manager/+bug/1066484/+attachment/3689222/+files/IMG_20130527_192438.jpg -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1066484 Title: long delay at shutdown/reboot - network-manager doesn't close correctly To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/network-manager/+bug/1066484/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs