New User Activation Problem

When a user completes the registration process they are transferred to a “Sign Up Complete!” page and get an email with an activation link, such as http://myDomain.com/activate/?key=xxxxxxxxx. However, when they click the link, they are redirected to an “Activate your Account” page and the message “The user is already active.” appears in a purple box. I checked the database and the entries look correct. The user is also able to login if they go to the login page.

How do I redirect them to a page that says they have successfully activated and can now login (or something similar) instead of the “Activate your Account” page?

BTW, I don’t know if it’s related, but I get the following when WP_DEBUG is true

PHP Notice:  Undefined index: ws_plugin__s2member_registration_return_url in ...wp-contentpluginss2memberincludesclassesregistrations.inc.php on line 985

Thanks for any help