I'll admit upfront that I'm not sure how registrations are supposed to work, so far for testing I have just added users in the admin back-end.
Anyway, with the social theme there are theme options for altering the text in the header where a user is not logged in giving them a link to sign-up. The default links to yoursite.com/register/ which I have edited to, ahem, mysite.com/register/.
But clicking on that link just reloads the same page, no changes.
If I manually type the url into my browser it just loads up that non-logged-in page.
Looking at the theme directory, there is a registration folder with activate.php and register.php in it.
Sorry if I'm being a bit thick, but could I get some pointers as to how to set things up so that there is some kind of registration page?