New sites in network cause a redirect look

Hi,

I am using Pro Sites to create a network. I chose to use extensions for the new sites and I just tested this by creating a new site. I got the email from WP saying that my new site was created, but when I go to the login I get a redirect loop.

1. The login page I was sent is http://prohealthsites.org/template/wp-login.php (where "template" is the name of the test site). Is this what it's supposed to look like? How do I avoid the redirect loop?

2. I'm starting to think that I should not have selected to extensions for the new sites. I remember reading that this cannot be switched...is this the case even if I don't have any site on the network? Is there an advantage to using one method over another?

Thanks so much!