WordPress MU

I am writing a login script that will allow my users of my blog to register within the blog in the side bar. I am adding additional usermeta data at registration time and querying my own company database with the information the provide to check whether or not I want to have them register for the site. I ask for their password and username also at that time.

So far, everything is working, creates the user and additional usermeta data but when I try to log them in it doesn't seem to work. I am using:

$result = wp_login($_REQUEST["user_name"],$_REQUEST["password"]);

$result returns a '1' but user is never logged in. What am I missing?

Thanks.