bp-social signup goes to http://yoursite.com/register instead of my registration page

Hi, I have a very basic question: I have installed the latest versions of Wordpress, Buddypress and the WPMU theme called bp-social. I have done no customisation, this is a fresh installation.

When I click on "Sign-up here »" it goes to http://yoursite.com/register instead of the registration page that I expect to see with my bp-social theme.

I have searched for the files and can see two locations that reference http://yoursite.com/register
\wp-content\plugins\bp-social\_inc\functions\options-functions.php
\wp-content\themes\bp-social\_inc\functions\options-functions.php

My questions are:
1/ do I need to change the link in these files to the correct registration page?
2/ if so, what do I change the link to?
3/ do I change it in both files?
4/ do I need to change the files at all, is there some configuration setting that I can't find?

Thank you for the help - I know this is a very basic question but I'm new to wordpress/buddypress. I have searched the forums and see a lot of messages in this area, but can't find one that helps me solve my problem (but I'll keep looking).