Problem adding users via MembershipRequest Webpart

I am having an issue when I add the MembershipRequest Webpart to a page and then try to add users. When I click <register> I just get an "unknown error" with the continue button. Perhaps I did not configure the webpart correctly? Can you point me in the right direction? Is this webpart customizable, meaning can we have the user supply more information (i.e. address, phone number, etc.)?
Also, are the Pages/ThankYou.aspx, Pages/PasswordQuestion.aspx, and Pages/ChangePassword.aspx included in the wsp? I can only get to the ChangePassword.aspx?
We are on a tight deadline with our website going live on 12/9 ( Any help would be greatly appreciated. Thanks so much!

The unknown error message just tells you that an exception has occurred.  If you check your SharePoint log file, you should be able to find all of the details.  Usually the problem is sending an email, so make sure that your email/smtp server is properly configured in SharePoint.

The layout of the web part is customizable with an ascx template. Unfortunately if you want to add new fields, you'll need some backend code to save the fields - so you will end up having to modify the source code.

The pages listed in the FBA Configuration are not included.  They are actually for filling in variables in the email templates.  The default templates only actually use the ChangePassword variable.  I probably should remove the other two to reduce confusion, but I don't want to break backwards compatibility in case somebody is using them in their email templates.

Thanks for the quick reply. I do know that our smtp server is not active yet, so that is most likely the problem.

Regarding the additional fields, do I have access to the source code? I tried to open up the solution, but it asked me for a TeamSite password.

You do.  It's just trying to connect to TFS - just hit cancel and it will open without connecting to TFS.  You can then remove the TFS connection if you like, and add it to your own source control system.