Be warned aspnet_regiis might change the version of .NET on your Virtual Directories
Yesterday we ran aspnet_regiis in an effort to get WCF working on our server (see this KB article for details on that http://msdn2.microsoft.com/en-us/library/ms752252.aspx) and all heck broke loose. Apparently the tool went through the websites and virtual directories on our server and change some of the ones set to .NET 1.1 to .NET 2.0. It was strange that it was only some of the directories and very frustrating to find, but it is fixed now and I thought I would share it with you all.