Hi, MCR,
If you've double checked your avatar size to make sure it's 100 x 100, you also need to check to make sure "enable avatar" is selected in your profile. If "no" is selected, it won't display. After you check these things, your avatar should display at the top of that profile page. If it doesn't display, try uploading the image again. Make sure that you click "update" after uploading the file, and click "save" after all the updates are made.
If you have any problems, let me know.
Sincerely,
Katie Streeter