Check your margin settings. Type '''about:config''' in the URL bar and hit Enter. ''If you see the warning, you can confirm that you want to access that page.'' Filter = ''margin'' - then look at the left and right margin settings for any that look grossly incorrect - the setting is in inches. Some users with that problem have reported settings like 2.7235879 - IOW a very long numeric string after the decimal point. Right-click the Value and select Reset or Modify. 0.5 or 0.25 are appropriate settings if you elect to Modify.