Please don't use offsite avatars. Rather, upload an image and have it hosted at GD. If necessary, just download the image from the net to your PC first and then upload it. It'll be automatically resized if it's too big.
Avatars shouldn't be larger than 10KB, but with offsite avatars this is impossible to control. Therefore, they have now been disabled. All unnecessary graphics are troublesome for users with slower internet connections, such as for many of our friends in India.