john_doe123, did you try normal browsing with Firefox in safe mode? If you don't know how to get the mode, or deleted the link from the Start Menu, input in a Run box "firefox -safe-mode".
Also, and this is just a shot in the dark, it would be a good thing to deinstall both Adblock and the Filterset.G updater, and go with AdBlock Plus. AdBlock has some unresolved problems, and the Filterset.G has been know to cause some other ones, apart from being overzealous in what it's blocking.