Hey Ive got this problem when i start up mozilla there is a gray spot about 4 inches talll that i cant seem to get rid of at the bottom of the screen and its starting to bug me cause i cant do anything about it and i cant see the whole screen a little help here?

Tried a new profile? ... or send us a screenshot.

Do other browsers (e.g. Internet Explorer) do the same?

Place your curser on the edge of it until you get an arrow pointing both directions, left click on it and drag it down towhere you want it.