Microsoft Tech support has been working with us on this by phone for 15 days now, but we still have not been able to resolve the issues. The first issue is when using Windows groups for roles: A user in the group is not recognized as being in that group and the user is denied access to the secured folder on the web site and to the sitemap for URLs in that folder.
The second issue is with the user not being recognized in a local group on my development machine running the website with my local IIS server. (This was a suggested approach by the Microsoft tech support rep assigned to our case.) I have been able to get that method to sort of work in a test project that does not connect to SQL server, however I run into problems when using it in our actual project, which does connect to SQL Server with WIndows authentication. If I use <deny users="*">, which works find in that little non-data-aware test project, I run into a problem with SQL server treating me as connecting as anonymous.