Geocode and Query Limits : See the answer here under FAQ
As far as that one particular site, was it imported in a bulk CSV file?
Check to make sure the address is correctly added, and if Google cant geocode it and you can find the lat/long then put it in manually (option not the best but it does happen). You may want to try t the PO box on the second line or eliminating it and adding it afterwards if you absolutely need to have it. Google will have difficulty geocoding a location of a PO Box, but again I am not sure if that is your issue or if it is bad data in your CSV file or your server.
If you need someone to login on your site that is a paid support option, the developer has another paid support customer he is helping at the moment, so having some sort of paid support will get you on his schedule. If you just want or need someone to review your CSV file you can opt for email biz support.
how google query works:
Google Geocoding and API