Ever since upgrading to Firefox 4 on Windows 7, when I attempt to restore down the Firefox window (either with the button or by clicking and dragging the menu bar down) Firefox will not revert back to its saved window position. It becomes windowed instead of full screen, but the window is the side of the screen and I must resize it again. I've attempted the menu bar fix (starting in safe mode and reverting the menu bars) as well as deleting localstore.rdf. This did not solve the problem though. I have dual monitors as well.