In Firefox 10, Mouse cursor disappears on address bar or search bar after some time, or I guess after visiting a certain site which I paste below. I can not see which part of the word I click on the address bar or search bar for correction because there is no mouse cursor. After Clicking on tools and options then cancel, mouse cursor appears ( I make no change to options) or when I click on customize on the navigation bar, then icons appear I click cancel again with no changes, and mouse cursor appears again (as you can understand some option windows trigger making it work even no change is made). I uninstalled firefox 10 only for this reason. Returned to Firefox 9. Safe mode - Same problem happens. So no addon problem. And same thing happened in another operating system, so this is not a fault of some installation.