Ubuntu's NetworkManager is Flaky

The debate rages on as to what component is actually causing the problem: NetworkManager, wpa_supplicant, drivers, or something else. But the problem is clear: Frequent disconnects, particularly in an environment where multiple access points provide access over a single SSID.

Either way, replacing NetworkManager with wicd resolves the problem.

sudo apt-get install wicd

After you've done that, wicd-client will start in your tray on the next login.

If you want, you can also configure it through the wicd-curses interface. One oddity, though, is that the curses interface is case-sensitive.