Addition: I just looked at my log: which output the following:
PHP message: PHP Notice: Undefined variable: output in /tiredofit.ca/wp
-content/plugins/wp-gpx-maps/wp-gpx-maps.php on line 670" while reading response
header from upstream, client: 127.0.0.1, server: tiredofit.ca, request: "GET /s
tats-logs/2011-12-07?ajax=true&width=80%&height=60% HTTP/1.1", upstream: "fastcg
i://unix:/var/run/php5-fpm.sock:", host: "www.tiredofit.ca"
Not sure if that will help.