Hi all frinds i create a pppoeconf connetion and install networ-manager-gnome but i have a problem with nm-applet when i run this command in finally for creat vpn nm-applet &

i get this error
root@bt:~# nm-applet &
[1] 1710
root@bt:~# An instance of nm-applet is already running.

** (nm-applet:1710): WARNING **: <WARN>  constructor(): Couldn't initialize the D-Bus manager.
anyone can help me for solve this problem sory for my bad english

apt-get install network-manager-gnome
    cp /etc/network/interfaces{,.backup}
    echo ""auto lo"" > /etc/network/interfaces
    echo ""iface lo inet loopback"" >> /etc/network/interfaces
    service network-manager start
    nm-applet &
thanks in advance