Yeah there's a huge difference. This has been going on for years now. Basically photobucket and tinypic (tinypic didn't use to do it, but lately I notice TP is doing it too) reduce the quality of .jpg files. Sometimes not immediately after uploading, but eventually they do. If you upload icons as a .png file then there's no problem, but any .jpg file on both PB and TP get reduced in quality. It always makes me really sad to see that to be perfectly honest (I used to always try to make people aware of that but most of the time they didn't seem to notice; you can always tell as well by the file size though).