Grey bar in firefox

[V4NT0M]

I'm using the twenty ten skin but had this with a few skins, I don't use the status bar but I have this annoying skinny bar at the bottom, anyone know how I might shift it?

 

[SiriusB]

I have it too. I never noticed it until now. Thanks a lot Sky!

EDIT: At full-screen I can hardly see it is there [at 1680x1050]