Firefox "Save Image As" doesn't work, stops, is broken or disabled.

This happened to me in Windows XP. If Firefox Save Image As function doesn't work, stops, is broken or disabled; fix it doing this: Close Firefox, search for the file downloads.rdf, and rename it to downloads.oldrdf (or any different extension). Restart Firefox.

This also fixes the dissapearance the download window that appears when you download a file.