Thanks to a note from Dave Burke I learned that comments had stopped working after the upgrade to CS2008.5. It turns out that the upgrade had turned off the ViewState on all of the post.aspx pages, which I had turned on previously to enable the Invisible CAPTCHA scheme that I was using. I have again turned on the ViewState for the pages that require it. If you notice any quirkiness, please let me know.
I'm taking a little time right now to announce a new project that is going to be released very shortly. The ASP.NET Live Membership project is 100% compatible with the existing ASP.NET Membership System in the .NET Framework, but will use a different database schema and replacement set of stored procedures. Check out the new ASP.NET Live Membership blog where a more detailed description of the project has been posted.