S2Member is excellent. It tackles so many of Wordpress' shortcomings and seems to do a really solid job.
But I want still more control over the registration process, so I copied wp-signup.php code to a custom template/page, added a URL rewrite to htaccess and made a few other minor changes - fixed paths to required files, changed action="wp-signup.php" to action="". It works fine and opens a world of new customization possibilities.
Unfortunately it breaks some S2Member functions. Firstname, Lastname are not stored, Display name is not set, and the custom welcome email is ignored - registrants get WP's obnoxious 'Dear User' default email.
I understand I was asking for trouble and that this is not a tech support channel, but if anyone has any idea where the problem could be, please let me know.
Is it somehow hardcoded in S2Member that registration form data has to come from wp-signup.php?
Are there required S2Member files/functions that go missing when you move the wp-signup code?
Something else I could check?
FYI, I'm working on a fresh Wordpress 3.3.1 Multisite Blog Farm installation with no other plugins activated.