Many websites display their images in the background so a normal right-click and save-image-as will not access them. Often, a blank or transparent image is placed in the foreground, which *will* be saved. That might be what you're seeing.
If you're viewing the site with IE7, right click on or around the image until "Save background as..." is available, and see if that gets the image you want.
If viewing the website with FireFox, then right-click on or around the image and see if "View background image" is available. Once you view the image by itself, and it's the one you want, then "File>Save as..." or right click and "Save image as..." should get you what you want.
Be aware that images guarded by backgrounding are probably copyrighted, and that distributing them to others (including putting on your website or social webpage) is probably not permitted.
