twentyeleven theme in WordPress - Nginx as reverse proxy to Apache2

[Loggy]

Actually it's more serious than just the image.  If you add a new comment
when not logged in, the whole post with the new comment is entered into the
cache and served OK.  But an immediate additional comment added is not
served because the cache hasn't expired.  The comment count is also not
updated.  

I have  tried adding the Nginx proxy cache integrator which adds effectively
expires the cache where particular types of cookie are found but a visitor
does not (in general) result in a cookie so the image problem at least
remains.

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,230916,230919#msg-230919