If you have altered the Spry code then you should only be getting the server side validation failing now. If this is the case you should be able to remove this line of code from the top of your page:
$WAFV_Errors .= WAValidateZC(((isset($_POST["UserZip"]))?$_POST["UserZip"]:"") . "",true,true,true,true,true,18);
This will prevent the zip code server validation from running.