one parameter missing from GeoIP data via FCGI

[Dean]

I'm running v.0.8.49 with GeoIP using both a city and a country
database.  All of the GeoIP-generated parameters passed via FGCI seem to
work great, except that $geoip_postal_code comes through empty.  

I've checked my fastcgi_param declarations several times (my symptoms
seem to point to a config issue since only one variable is impacted) but
everything looks in order.  MaxMind states that they don't have postal
codes for all IPs, but I've tried on a few different IPs in the same
general area here in the US with the same results--no postal code
reported.  I don't believe it's an issue on the FCGI application side,
since I'm just doing a dump of the whole environment at this point.

Looking at the logfiles (debug level logging), the only thing out of
order is 
    
    2010/08/23 17:39:03 [notice] 13420#0: getrlimit(RLIMIT_NOFILE):
1024:1024

which does not seem like an issue given that the number of served files
will be less than 10 on this machine.  

Any suggestions as to how to debug the parameter issue?

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,122988,122988#msg-122988