Javascript not working from external link

Hi,

I have installed Teamcity on Server 2008 on port 8181. I have added ARR and URL rewriting to IIS and set inbound and outbound rules to handle requests for teamcity.domain.com (-> localhost:8181) and an outbound rule to rewrite href records from localhost:8181 (->teamcity.domain.com).

When I access localhost:8181 on the server it all works well (image attached) but when I access it externally is says to enable JS but it is anabled (Image attached).

Any ideas?

Thnaks,

Andrew

UPDATE:

The login page uses JS window.location.host and I assume appends the source 'path' to that uri to source the JS and CSS etc but when I run javascript: window.location.host in teh address bar it returns the correct url. If I then append a JS src path it says server error 500