The new notification system in the latest Ubuntu release broke the functionality of disabling the notifications of NetworkManager (there are no more buttons in the bubble).

I propose the same solution that Banshee or to some extend Pidgin uses: add a checkbox to the context menu of the tray icon with "Show notifications".

I consider the notifications of NetworkManager highly annoying and irrelevant since I expect the wireless network to work if I boot my machine. If it doesn't work the tray icon already clearly indicates that.

Therefore being able to disable the notifications again would be highly appreciated, although it's not really your fault in the first place.