I have noticed the same situation on a installed and up to date version of Ubuntu 12.04 (32bit).
Clicking the NetworkManager icon only four items were available. But after deactivating and then activating the "Enable Wireless" option, all the items were again available.
I tried to log out and start a new session and also to reboot the system. Everything fine in both cases, the NetworkManager was still showing all the items.
I have noticed the same situation on a installed and up to date version of Ubuntu 12.04 (32bit).
Clicking the NetworkManager icon only four items were available. But after deactivating and then activating the "Enable Wireless" option, all the items were again available.
I tried to log out and start a new session and also to reboot the system. Everything fine in both cases, the NetworkManager was still showing all the items.