@Setanta,
I had that happen with ff too.
In order to see all the game screen, I had to click on a word in the game and just hit TAB until my cursor went down to the bottom. ONLY then could I see it.
I still get that sometimes but ( and I dont know if this fixed it or not..) after I went through and selected which pop ups to allow on games, I have not had that problem as
much since then..
Yes it still happens.... but when it does, I close/reopen and voila . Screen normal.