Ubuntu 12.04 Wireless unmanaged

When installing Ubuntu, and during install You choose to use wlan0 interface.
On first system boot wireless becomes unmanaged, and You can’t choose wireless AP.

solution is to edit file /etc/network/interfaces
There should be lines like

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auto wlan0
iface wlan0 inet dhcp
   wpa-ssid wifi-name
   wpa-psk wifi-key

delete those lines and reboot computer. Network manager will be able to control wifi.