There were some reports that users actually couldn't download their images hosted on Photobucket because of some sort of image corruption that kept happening. I've seen this myself a few times when trying to save images from Photobucket; you'll end up with images that are totally distorted, with a vertical height of only 50px or so for an image that was once thousands of pixels tall. Again, not sure it's intentional on Photobucket's part or just sheer incompetence, and again I suspect it's a little bit of both....
I was getting that last night. I was trying to download some of the images I had posted to one of the threads I had and every time I clicked on the download link it tried to download a 0 byte file. In the end I had to right click on the image and select 'save file as' to down load them.