Check the back button history. Mine often fills up with googlead addresses (using IE) and none of the so called "cures" I've read on the Net has worked. It's not like I can change the work PC browser willy nilly. It may not be the problem you have but it's worth chiecking.
If you mean the back button on AB in the top left corner, you can get round the problem (which exists with an old version of IE) by right clicking on the back button and then selecting the item you want