gnomeでスクリーンセーバーや画面のロックを使いたいのですが、
以下のようなエラーが出ます。どうすればよいですか？

> dmesg
pid 1099 (gnome-screensaver), uid 1001: exited on signal 6
pid 27016 (gnome-screensaver), uid 1001: exited on signal 6
pid 27018 (gnome-screensaver), uid 1001: exited on signal 6
pid 27054 (gnome-screensaver), uid 1001: exited on signal 6
pid 38082 (gnome-screensaver), uid 1001: exited on signal 6

> gnome-screensaver
process 38082: arguments to dbus_connection_send_with_reply_and_block() were incorrect, assertion "connection != NULL" failed in file dbus-connection.c line 3168.
This is normally a bug in some application using the D-Bus library.
  D-Bus not compiled with backtrace support so unable to print a backtrace
Abort