Network is not working anymore - Ubuntu 12.04

Managed to get mine going just now after upgrade to Ubuntu 12:

Edited /etc/network/interfaces:

The line #iface eth0 inet dhcp was commented out; I removed the "#".

Then I ran sudo ifup -a, and it brought up the network.

Sorry about the network manager, folks, but if there's one piece of software that should be 110% ready before a release, that would be it.

I had a similar problem which was caused by a network-manager package update. I could solve it as follows:

1. Download the previous version of the network-manager packet on a different computer from this page (scroll down and click on your cpu architecture).

2. Copy the file to your computer and install the package via sudo dpkg -i packagename.

3. Reboot.

4. If this solves the network problem you can start synaptic, search for the network-manager packet, select it, go to "Package" in the menu and then click "lock version". Otherwise Ubuntu will try and update the package again.