Rockzmom. Sorry, no luck so far. i might try and have another look tomorrow.
I found the ap=1 by clicking on a photobucket video with autoplay and then looking at the source code. So if you happen to have come across another photob video with those settings then we should be able to get the code from there.
Getting rid of the related videos may be a lost cause however.Allow pro users to remove the related videos feature on video player.
EDIT: I tried googling it again but still no luckt. Shame cos this is useful stuff to know.