If you are like me you might have had difficulty uploading an avatar picture because of the size they require. This very helpful tip was shared with me and it worked!
Upload your chosen picture to your computer
Go to http://www.shrinkpictures.com
Upload your picture there and make it 100 x 100 pixels
Now upload this picture to your computer again
Go to your profile and click on your avatar and upload the smaller picture.
Hope this helps!