Whenever there's a window, or anything, that's 'on top' (or rather in front) of Firefox 4 browser, it becomes invisible at first. Then if I hover on a button or something of that window, that button or whichever I hovered would appear, while everything else is still invisible unless I hover on them too. Here is an example of me opening Tools > Options. http://i1014.photobucket.com/albums/af266/xCrepitus/firefox/ff1.png http://i1014.photobucket.com/albums/af266/xCrepitus/firefox/ff2.png http://i1014.photobucket.com/albums/af266/xCrepitus/firefox/ff3.png Now after I hovered almost everywhere: http://i1014.photobucket.com/albums/af266/xCrepitus/firefox/ff4.png Next example is when I open windows at bottom left. http://i1014.photobucket.com/albums/af266/xCrepitus/firefox/ffa1.png http://i1014.photobucket.com/albums/af266/xCrepitus/firefox/ffa2.png Now after I hovered almost everywhere: http://i1014.photobucket.com/albums/af266/xCrepitus/firefox/ffa3.png Things I've tried: Disable all add-ons. Disable visual themes EDIT: I tried running firefox in safe mode and it fixed it BUT is there a way to fix it without running in safe mode?