Well, clearly you've uncovered the evil twist in my plan.
I've specially written specific software that recognizes your profile and messes with your mind, changing the format of your buttons, just to annoy you!
I don't know, but you must be doing something odd. When you put the pic (url) in, do you just need to scroll down the page to see the post button? It can't just disappear. The Photobucket app works, you know that. So sorry, but it must be operator error!