I am trying to consume data from a webservice published by a 3rd party. I have a SDK win-app that is able to call the service (from my dev machine) and get results, but a web-app (running on the same machine) which has the same code, is getting nothing back.
My question is:
Is there a difference (from the server's prospective) as to what type of app calls the web service?
Nope. To the server it is just a request. Both apps communicate with it through HTTP and SOAP.
As Kevin said, to the server it's just a request.
I would recommend running Fiddler2 or WireShark to see what's happening at a network level. Then you can see whether the problem is that the client is sending a different type of request which the server can't understand, or whether the server is sending back information but the client can't understand it.
No.
Make sure your web-app isn't hitting a firewall rule trying to make the outbound web request. Also make sure the user you're running your web-app as has sufficient permissions to make the web service request.
What do you mean when you say you have an "SDK win-app"? Is there some SDK code that calls the web service, or are you calling it directly through a Service Reference? If the former, then maybe there's a permissions or Code Access Security issue.
Also, you say you get nothing back. Can you elaborate? Does the call not return? Does it return null? Does it throw an exception?