"No credentials supplied" response

Hi,

I get this response when comsuming a web service. It seems to have 
something to do with SSL certificates.

I know because..

FhttpRIO.HTTPWebNode.InvokeOptions := [soIgnoreInvalidCerts];

This works when I try it against their test web service which actually 
has an invalid expired certificate. However the certificate seems to be 
valid on the deployment site to which I have no access and most likely 
has a valid certificate and I get the "No credentials supplied" 
response. When I use the default HTTPWebNode.InvokeOptions (i.e. does 
not ignore invalid certificates) when consuming the test web service I 
also get the "No credentials supplied" response.

Any ideas how I can resolve this? Can one somehow pickup and set the 
certificate information at runtime?

Some more info..

The Delphi application consumes another web service for eBusiness 
between 2 separate companies.

The test web service is available on the internet via 'https://external 
ip' (SSL). On the deployed site it seems be connected via a VPN to the 
web service 'hosting company' and the web service address is 
'http://internal ip' so could it have something to do with the VPN SSL 
certificate?

Thanks,