When I add/edit a Stack Exchange site on my Careers page I got repeated a
Meta Stack Overflow
See this screenshot:
I am using firefox 4.0.
That's your browser displaying the ALT text of an image it couldn't download. It may be related to our load balancer acting up for a minute (about half an hour ago); in that case, it should resolve itself.
Also note that Firefox 4 is now considered ancient. We don't support it anymore, and neither does Mozilla. You should upgrade ASAP.