connection established notifications

Every time I connect, disconnect and connect to my wifi net appear a new in notifications of gnome appear a new buttom saying "Don't show this message again". If you do it four times, you have four buttoms.

It happened me in a live session selecting Install option in the first menu of the live CD and with spanish language. After trying it a lot of time I obtain something like the snapshot attached. If I click on "Don't show again" it seems don't happens anithing.