I recently upgraded to Firefox 4.0 from a version of 3 that worked perfectly. Now I am constantly getting hourglasses as pages try to load. Many times the screen will just display a solid white background while I look at an hourglass. Often times the program will say "Mozilla Firefox (Not Responding)" in the bar at the bottom of my desktop. Sometimes this hanging can be triggered by trying to move the scrollbar on a webpage downward. Other times it just can't load the page right from the outset.