For about a month now whenever I "save as" such as images(doesn't matter what type) or try "save page as" it will automatically add a ".rb" file extension to the original extension. So if the image is called "image.jpg" it will look like "image.jpg.rb" and its really starting to get aggravating to keep deleting the extra extension every time I want to save something. The only thing that doesnt do this are programs and zip files and such. I also tried "saving as" on other browsers and it doesn't affect those. Its only on Firefox. I have updated firefox a few time after this has happened and nothing helps.

Firefox v 10.0.2 Windows 7 64-bit