What browser are you using? Older versions of Internet Explorer (or AOL) save the images as bitmap files. If this is the case with you, I'd recommend upgrading to a newer browser, such as:

Mozilla Firefox: http://www.getfirefox.com
or
Google Chrome: http://www.google.com/chrome/

Both are 100% free, completely safe, and will significantly speed up the loading speed of websites you visit.