I.E. 5.5 maximizes using wrong coords

Ever since my browser window was unexpectedly resized to about 1/3 of its original size by a website the other day, I have had the same exact problem whenever I click the Maximization button: The browser window maximizes with its left edge at aprox.80 pixels away from the left edge of the desktop and its top edge about 80 pixels away from the top of the desktop. Obviously, when it is maximized, it cannot then be grabbed by the mouse and dragged to correct alignment against the upper left desktop corner in order to fill the entire screen, as it should. How do I restore the correct alignment coordinates? What has happened to cause this?