Still playing with pictures

And it's still not working. I went to Blogger's help files and discovered that other people are having the same problem. Unfortunately, the solutions that have been suggested aren't working-- I've tried resaving the file and changing the name, and I'm still getting the "File type not supported: image must be GIF or JPEG" in spite of the fact that the images ARE GIF and JPEG. This web stuff is hard enough without having things malfunctioning.