Thanks for bringing this to our attention.
i have logged a bug for the problem to have it corrected in a future update.
the zip validation code:
$WAFV_Errors .= WAValidateZC((isset($_POST["UserZipcode"])?$_POST["UserZipcode"]:"") . "",,false,5);
should be:
$WAFV_Errors .= WAValidateZC((isset($_POST["UserZipcode"])?$_POST["UserZipcode"]:"") . "","",false,5);