...and MS will make sure not to support it every time they update your IE. Thus the IE spiral begins, constantupdating followed by constantupdating to make it work again after the update removes the unsupported functions. Corporate conclusion...
http://news.cnet.com/8301-13860_3-10360850-56.html
...Policies written with roles rather than users are preferable, as administration is simplified and doesn’t need constantupdating. When a user makes a request to a .NET Web application, .NET examines the web.config file in the application...
http://documents.iss.net/whitepapers/asp_net_whitepaper.pdf