Product Theme and Membership plugin sign up page

Hi,

Multisite 3.1.1, Product Theme with Membership plugin, no BuddyPress.
I created a sign up page as requested by the Membership plugin domain.com/register
and then entered the URL in Admin>Appearance>Theme Options>Branding>Enter a custom page if you've created one for your login but a new user is still directed to /wp-signup.php

How do I get the Product theme sign up button to direct to the page that I created since the Membership plugin does not give the option to point to the wp-signup.php?

Thx