On a 2008 R2 server we have shared configuration set and also IPv4 Restrictions, however the restrictions don't seem to work if shared configuration is on. I have only found this issue elsewhere online at http://forums.iis.net/p/1162818/1977556.aspx (after a considerable time searching).
I was wondering if anyone is able to point me in the direction of anything official to back this up or if anyone has any further information on it. Or is it just a case of an undocumented "feature" of IIS?!