Initially my work computer was using DHCP, and so on the Network Manager widget, I had a Auto Eth or something like that showed up on networkmanager widget that received and used the provided DHCP server address.

But then I moved to a fixed IP, and Network Manager started to say that Wired network is Unmanaged, because the IP was now fixed by /etc settings.

Anyway, I've returned to DHCP again, but networkmanager still says that the Wired Network is unmanaged and I've lost the Auto Eth.

How do I get "control" again? Or in another words how to I go back to default settings?

See http://wiki.debian.org/NetworkManager

According to that page, NetworkManager will only manage interfaces not mentioned in /etc/network/interfaces.

Thanks!

It's solved.

In my case the file /etc/NetworkManager/NetworkManager.conf is named nm-system-settings.conf but everything else is the same.

So I deleted all references to eth0 on /etc/network/interfaces and change the managed=false to managed=true on the above file.

Restarted services, and it worked right away.