Comment 296 for bug 191889

The 'iface eth1000 inet dhcp' trick didn't quite wok for me, but I'm not entirely sure I have the same issue. I'm using Ubuntu 8.04 with a wireless connection (Intel 3945), and I use Opera rather than firefox, and what I've been experiencing is when I boot Ubuntu, the network manager applet shows "Networking Disabled" - I can't view SSIDs, it doesn't give me the option to create a network or manually configure a network, nothing. I run "sudo dpkg-reconfigure network-manager" and it starts behaving normally.

So, it almost seems that whenever I shut down the laptop, something isn't getting cleared up, and when I boot it back up, whatever didn't get reset is jacking up the configuration so that it thinks networking is disabled.