the curser includes a text box from a previous image or link when the curser is positioned on the side of the page. i click and it goes away but only to return again on the next launched page. how do i get rid of this?

the cursor includes a text box from a previous image or link when the cursor is positioned on the side of the page. it will mainly happen when i hit "back" from the page i was on. i click and it goes away but only to return again on the next launched page. i also keep several tabs open and it will carry over to any one of them i go to. how do i get rid of this? == This happened == Every time Firefox opened == when i upgraded to most recent version 3.6.8