Comment 8 for bug 997900

There are plenty of askubuntu similar issues. (e.g. http://askubuntu.com/questions/139036/ubuntu-12-04-says-wireless-is-disabled-by-hardware-switch) and launchpad answers too.

The wireless shuts down and won't turn on again after the switch in turned on. Proposed solution is to run "rfkill unblock all" from terminal.