Quit option in Drop-Down Menu

If network-manager is active and one selects System->Administration->NetworkManager, a second network-manager icon will appear in the notification area. Selecting again causes a third and so on. This leads to multiple instances of network-manager fighting each other, creating the illusion of a slow network.

Two points:
1) Network-manager should not, by default, start up if another instance is already running.
2) Network-manager should provide a means to completely shut it down from the notification area icon. Yes, killall will do the job, but I want something for the non-geeks in my charge.

Ubuntu 7.04 (Feisty) x86
uname -a output: Linux zaphod 2.6.20-16-generic #2 SMP Wed May 23 01:46:23 UTC 2007 i686 GNU/Linux
Notification Area 2.18.1
NetworkManager Applet 0.6.4

ProblemType: Bug
Architecture: i386
Date: Mon May 28 13:08:50 2007
DistroRelease: Ubuntu 7.04
ExecutablePath: /usr/bin/gnome-panel
Package: gnome-panel 1:2.18.1-0ubuntu3.1
PackageArchitecture: i386
ProcCmdline: gnome-panel --sm-client-id default1
ProcCwd: /home/dave
ProcEnviron:
 PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: gnome-panel
Uname: Linux zaphod 2.6.20-16-generic #2 SMP Wed May 23 01:46:23 UTC 2007 i686 GNU/Linux