My question is the same as this one.
I put my stackexchange flair at the bottom of my sites:
And get a "profile for Ninsuo on Stack Exchange, a network of free, community-driven Q&A sites" link instead of my nice flair.
By opening Firebug, I can read the following error:
Or as text:
NetworkError: 500 Internal Server Error - http://stackexchange.com/error?aspxerrorpath=/users/flair/378431.png
I did not tried to update a new picture - just in case you want to get further first.