Replying to Am i doing something wrong, or does photobucket drop links to pictures after several days?

My photos that I link to threads with [IMG] format work fine for a couple days and then the link disappears and the stupid photobucket thing comes up in place of the picture. The photos are still in my photo bucket album, nothing has changed. The same has happened with photos I have uploaded to the pictures section on ns, using the photobucket url link. Anybody know what the hell is going on? Is it something I am doing? Is there a better place to host photos, because this is really starting to piss me off. thanks