Custom signup error after upgrade - 4.2.19 to 4.3.1

I am using a local machine to develop and test my aMember/Wordpress installation.
My live site, running aMember 4.2.19 and Wordpress 3.6, developed and tested on this local installation, is up and running very nicely, no problems.
I recently updated my local/development site to aMember 4.3.1. from 4.2.19. Now, my customized signup template, created using the method found here: http://www.amember.com/docs/Custom_Signup_Forms, throws an error "An internal error happened in the script, please contact webmaster for details".
This custom signup worked prior to the upgrade, and the default signup template does not give an error. Everything else is working OK. I'm sure I'm missing something simple but I haven't a clue.

Update - CGI-Central provided this:

to fix an issue on 4.3.1 please edit /amember/library/Am/Form.php
and replace

class HTML_QuickForm2_Rule_Remote extends HTML_QuickForm2_Rule {
protected function validateOwner() {
return true;
}
}


with

class HTML_QuickForm2_Rule_Remote extends HTML_QuickForm2_Rule {
protected function validateOwner() {
return true;
}
protected function getJavascriptCallback()
{
return "function () { return true; }";
}
}

I made the change and the form now works without errors.