Comment 3 for bug 293228

I have similar issues. I've had issues with network-manager and avahi-daemon since I installed some opensync and bluetooth packages to sync my pda. I think it started because it tried to add my bluetooth dongle as eth1 and use avahi-daemon to set up local dns maybe? thats just a guess because i don't really understand what changes were made.

But the only way I could get it to reliably work is to turn off nm-applet auto start in xfce4-session-settings.
Then manually configure my static IP address and nameserver. I also changed the avahi setting to 0 below.

Don't know why or how this fixed my issue but it did.

~$ cat /etc/network/interfaces
       auto lo eth0
       iface lo inet loopback

       iface eth0 inet static
            address 152.19.35.137
            netmask 255.255.0.0
     gateway 152.19.1.1

~$ cat /etc/resolv.conf
nameserver 152.19.4.1

~$ cat /etc/default/avahi-daemon
# 1 = Try to detect unicast dns servers that serve .local and disable avahi in
# that case, 0 = Don't try to detect .local unicast dns servers, can cause
# troubles on misconfigured networks
AVAHI_DAEMON_DETECT_LOCAL=0