As scdub says, the images are .jpg files. It's possible that your computer setting got changed so that .jpg files aren't being opened properly.
Can you see .jpg files outside of bladeforums? Outside of your browser? Check any of your saved images.
I don't know what kind of computer or software you are using. On a Windows machine, each file extension (.jpg, .doc, etc) is associated with a program that opens the file. There's a system setting for this. If the setting for .jpg got changed somehow, you won't be able to open any .jpg image, including those in your files outside of your web browser.
If that's the problem, it's an easy fix to correct that system setting. How to do it depends on what kind of system you have.