add_header works in server but not in http?

[holstebm]

Okay, then, a little more detail.  In my Server block, I had an
add_header for Cache-control.  When I remove that add_header, the other
one in Http appears.  If I put both in Http they both appear.  If I put
both in Server they both appear but it seems that the add_header removes
the headers from the parent blocks.  I don't think that was the previous
behavior.

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,198143,198147#msg-198147