Make wired nework working with NetworkManager on Ubuntu 9.10

I have installed ubuntu 9.10 recently. At the beginning, NetworkManager can connect with eth0 automatically. After some days, it shows Wired Network - device not managed when I clicked NetworkManager. After some googling, I found the solution. Just change managed=false to managed=true in /etc/NetworkManager/nm-system-settings.conf.

 

Here is my /etc/NetworkManager/nm-system-settings.conf

 

# This file is installed into /etc/NetworkManager, and is loaded by
# NetworkManager by default.  To override, specify: '--config file'
# during NM startup.  This can be done by appending to DAEMON_OPTS in
# the file:
#
# /etc/default/NetworkManager
#

[main]
plugins=ifupdown,keyfile

[ifupdown]
managed=true