I've been trying for a a month, but for some reason today I must have done something different & it worked. Here's what I did today.
Up above the thread you'll see quick links, hit that & you will see User Control Panel - click on that then on the left side hit Edit Avatar. Click on Use custom Avatar (that puts a dot there, then go to Option 2, hit browse to get a picture from your computer (wherever your picture is on your puter go there to get it). Then hit save changes & it will upload your picture. Once you see your small picture up top you are done. Hope that helps. That is what I did today & it finally worked for me.