Comment 28 for bug 555571

This problem arose for me when my laptop went into some sort of dormant state (sleep or hibernate, I reckon). I was very pleased to find Dani's posting. For a full description of my experience, please see what I wrote at https://answers.launchpad.net/ubuntu/+question/126770 , starting with the posting that begins "Well, I have mixed results to report - and a new variable
thrown into the mix. Here's what happened."

I suspect there are other ways to get the Network Manager into this state, but I found one - do a complete purge of system power (on a laptop, in my case) when Linux is in such a dormant state, when I suspect it deliberately disables the eth0 and wlan0 devices.