Just in case if anyone bothers to track my blog here is an update. I have contributed two posts recently to our IIS/ASP.Net Support blogging site.
1. If you are seeing the following error during the IIS 6.0 Install/Setup:
Error writing encrypted data to the Web Server's configuration database (Metabase).
This post may be useful to you.
2. We had an article on http://learn.iis.net around how you can configure One-to-One mapping for client certificate authentication feature in IIS 7/7.5 but we did not have an equivalent for Many-to-One mapping. If you are interested you may want to follow the link below:
This post also highlights how you can use the cool Configuration Editor extension to manage IIS configurations including Client Certificate mapping and how easily and automatically you can generate code/scripts/commands to manage IIS features.