I am having a problem with an external web service that I cant seem to
solve.

I am working on a system which authenticates data, such as confirming
a persons identity. The system involves calling web services of
various data providers and processing the response.

One particular provider, exposes a web service which I call into and
return a job identifier.

Several seconds later the provider makes a web service call into a web
service which I expose that returns the results to me.

For my call into their web service, I was given a WSDL file. This
call works fine.

The problem is in them calling my web service. They only wanted a URL
to my web service and provided me with an interface which was
identified in their WSDL file.

When they call into my web service they are getting a 500 error from
my IIS. I have installed WSE 2.0 and implemeneted tracing.

Here is the error message from the Soap message in my Output Trace
file...

<soap:Fault>
<faultcode>soap:Client</faultcode>
<faultstring>Server did not recognize the value of HTTP Header
SOAPAction: .</faultstring>
<detail />
</soap:Fault>

Any ideas what is the problem?

Thanks
Jeff