SSL works on Internal Network But not from external site.

I have set up a virtual directory that contains a simple webservice. I have
set up an application underneath the root of the (non secure) site. This
application has been set to require SSL. If I browse to the asmx page from
the server I get a cert prompt and the page displays fine (the service
description). Also from my development PC attached to the network I have no
problems. However when I try and connect from an external PC I get:



Server Error in '/' Application.
------------------------------------------------------------ --------------------

The resource cannot be found.
Description: HTTP 404. The resource you are looking for (or one of its
dependencies) could have been removed, had its name changed, or is
temporarily unavailable. Please review the following URL and make sure that
it is spelled correctly.

Requested Url: /services/Service.asmx



this is after the server cert prompt.

I have tried various security settings and IIS tools but none are giving me
much help.
I had thought it was a permission problem (maybe at the file level) so tried
various permission settings but this did not resolve the issue.

Tech Setup
----------------------------------------------
Windows server 2003
IIS 6
Anonymous access allowed using specific account (ie not Iusr_XXXX)
No other authenticated access tick boxes ticked
Server Cert installed (128 bit not required)
IP address range = All Granted
Application running under it’s own App pool with dedicated AD account (for
access to SQL resources)

ASP.NET 1.1

Any help appreciated, or any ideas where to go next …..