Hi,
All of my opens are tracking as EU. I haven't looked into the code to see how you're doing geocoding.
Could the fact that my apache server is behind an nginx reverse proxy have something to do with it? I'm using rpaf (http://stderr.net/apache/rpaf/) on my apache server to get the forwarded ips from the nginx reverse proxy, and those show up fine in the apache logs.
Thanks!
mkm