Ok, today the notification icon showed up again, some more updates.
Result : the bug is still there -> I uncheched one of the packages, installed the other ones. Once these updates were installed, it refreshed things and RE-selected the update that I had UN-checked seconds before, thus ignoring the user input. So I unchecked AGAIN that remaining update, then clicked on the "Close" button.
Result: -> the notification icon is still lit in the gnome panel, and if I click on it again, that update appears to be checked AGAIN !
Ok, today the notification icon showed up again, some more updates.
Result : the bug is still there -> I uncheched one of the packages, installed the other ones. Once these updates were installed, it refreshed things and RE-selected the update that I had UN-checked seconds before, thus ignoring the user input. So I unchecked AGAIN that remaining update, then clicked on the "Close" button.
Result: -> the notification icon is still lit in the gnome panel, and if I click on it again, that update appears to be checked AGAIN !