Enigmapond said: This is not true as I have mine set to show when updates are available. It is not there when there are none but when there is, the icon will appear and the Manager won't appear until the icon is clicked. So I was instructing based on how I have mine set up which works very well.
There are only three options, none of which should have anything to do with the method used for informing users about available updates.
Instead they allow you to switch between automatically installing security updates, downloading updates in background or notifying about them. "Only notify about available updates" is the default setting anyway, and without changing the gconf key should use the default method of notifying about them, which is popping up the Update Manager (max once per seven days by default, unless there are security updates) window instead of showing a notification icon.
I'm not sure if the method for notifying about them was already changed in 10.04 (which you are running based on your profile), but those options really have nothing to do with it. Perhaps 10.04 still sued the old notification mechanism (I can't remember any more), you have at some point changed the gconf key, or are running a system upgraded from older Ubuntu version.