Saw this before version 2.2.2 and the solution was to use the current beta version of Apache (2.1.8-beta I think). Now I see it again for the new photo page.
Found some online forum message where they suggested to change the
output_buffering value in
/usr/local/lib/php.ini to something like "1048576" (1MB). I don't have pictures that large so I set it to "512000" (500kB). This solved the problem for me.