Description of problem:
Running 'gnome-control-center --help' in a terminal while the control center is already running closes the running instance.

Version-Release number of selected component (if applicable):
control-center-2.91.92-1.fc15.i686

How reproducible:
always

Steps to Reproduce:
1. Open Systen Settings
2. Open a terminal
3. $ gnome-control-center --help
  
Actual results:
control-center windows is closed and an error message is displayed in the terminal:
GDBus.Error:org.freedesktop.DBus.Error.NoReply: Message did not receive a reply (timeout by message bus)

Expected results:
The window should remain open and the terminal should just contain
$ gnome-control-center --help
Usage:
  gnome-control-center [OPTION...] - System Settings

Help Options:
  -h, --help               Show help options
  --help-all               Show all help options
  --help-gtk               Show GTK+ Options

Application Options:
  --version                
  -o, --overview           Show the overview
  --display=DISPLAY        X display to use