I have never had a problem creating a web site on this particular server until now. The server runs Server 2008, Exchange, and at least 5 other sites all with their own unique host headers tied to a single external IP. Recently, I added a new web site, redirected DNS, and added the host header to the bindings of the web site. When I try to hit it, I get a 403 forbidden error.
I then added another entry to the bindings, only this time with no host header name but using a unique port. Sure enough, after adding the firewall exception for this new port, I was able to hit the web site.
www.DOMAIN.com:8087 = Worked
www.DOMAIN.com = 403 Forbidden
The pic below is how the bindings are set up. I have tried the host header entry both with an IP specified and with a wildcard to the same effect. I checked all the directory permissions and those seem to line up. I have never seen this before so I am out of ideas.