Using Lubuntu 12.04.

Sometimes my wifi card stops working, but that is not what I'm asking about (I know how to get it working again). My problem is that, after it stops working, a network manager dialog pops up asking for me to enter the password. Then, if I don't enter one, ANOTHER of the same dialog box pops up again, and again, etc. If I am away from my computer for a while, I can come back to 50 or more dialog boxes, each of them taking their own spot on the window bar.

Any way to make this stop? I've searched online, can't find anything.