If you see this page, the nginx web server is successfully installed and working

I've been seeing this message on and off today:

If you see this page, the nginx web server is successfully installed and working

It happens if I try to use a forum's big orange plus to view unread posts there. Not doesn't happen all the time, but once a particular forum is doing it, it lasts a while, I'm guessing until another post arrives in that forum.

I cannot reproduce what you are seeing so this would be a good time to...
http://forum.arduino.cc/index.php?topic=175131.0