Saving images in Internet Explorer

Ever had a problem where you right click on an image in Internet Explorer, but the Save As dialog box only allows you to save the image as a bitmap (BMP) file? I have seen this for a couple of years, but never figured out why. And, the problem was inconsistent. Thanks to Eugene Siu, I now know why. The Internet cache is full. Purge it or increase it, close the browser, reopen it, and try again! Thanks Eugene, you are my new favorite blogger!!!!!