Our zipcode integration is coded and works fine. You may post code hacking instructions on photopostdev.com
I have removed your examples of how to hack the files to UK so as not to confuse people and thing there is bugs when there are not.
In fact in the code you posted you removed a security thing in the query which in your installation would allow a user to inject malicious url into your site
".intval($prodzipcode)." THAT IS A SANITISER you do not remove that