As of June 1, Photobucket has changed their policy in regards to hot-linking images. It used to be free and has been for years but unfortunately it isn't anymore. The now are asking for a $400/yr subscription fee to allow hot-linking. You will now notice any place a photobucket image was used has now been changed to the image below.
I would suggest you start using other methods to hosting images as I can't see them allowing free 3rd-party hosting anymore.