Changed document to window for position checks.
Changed document to window for position checks.

Looks like I was a bit to agressive with the search and replace in
commit 71689e8148abc818e91b40a78dcdcecac30c97d0. I blame IE8.

jasco/jquery-powertip,stevenbenner/jquery-powertip,jasco/jquery-powertip,stevenbenner/jquery-powertip,erthalion/jquery-powertip,erthalion/jquery-powertip