Comment 4 for bug 223263

I have seen this "grayed out Network Manager" issue on a few Hardy systems.
In every case there was an interface other than loopback configured in /etc/network/interfaces.

Please verify that your /etc/network/interfaces file looks like this:
-----------------
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

# The loopback network interface
auto lo
iface lo inet loopback
-----------------