Ubuntu panel problem

Problem: I can't find the network manager on top panel
Solution:
sudo gedit /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
Solution2:

1.gconftool --recursive-unset /apps/panel

2.rm -rf ~/.gconf/apps/panel

3.pkill gnome-panel 

ref:http://blog.csdn.net/wyzxk888/article/details/5934157