If you have a terminal open when the symptoms arise and try to start another program, vlc for instance you get :
jeremy@quartz:~$ vlc VLC media player 1.1.9 The Luggage (revision exported) Blocked: call to unsetenv("DBUS_ACTIVATION_ADDRESS") Blocked: call to unsetenv("DBUS_ACTIVATION_BUS_TYPE") -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/752891 Title: Dbus hangs using 99% cpu To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/dbus/+bug/752891/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs