trying to use integrated pipeline to authenticate all content with forms auth

http://learn.iis.net/page.aspx/244/how-to-take-advantage-of-the-iis7-integrated-pipeline/
I tried following the example there, but it's not working at all for me.
In IE8, i can't even get the login form to submit - clicking the submit button does nothing.
In chrome i can get it to submit, but it either keeps coming back telling me the login failed, or i get an invalid object error on line 296 (bolded) of the XmlMembershipProvider.cs file, which is:
                foreach (XmlNode node in nodes)
                {
                    MembershipUser user = new MembershipUser( Go to the complete details ...