Thread:Project:Support desk/Tabs at the top display weird when the AddThis like prompt displays

I have an AddThis widget in the site notice that displays a bar at the top of the page any time someone visits from a link from Google, Facebook, or other social networking services. When it displays, it seems to create a gap between the tabs and the page content. The code of the AddThis widget is here:

http://www.sturmkrieg.us/Widget:AddthisWelcome#.UUj2sFvwIbo

Does anyone know how I can fix this?

This is what it looks like: