Consume WebService - "Path property mus be set before [...]"

Good morning,

I am working a little bit with the NAV 2009 Marketing Demo and I was trying to use the Webservices that are provided by NAV. At first, everything worked well - I published a Codeunit with one Method that returned a text.

Yesterday I continued with "consuming" pages in VS2008 and I always got an InvalidOperationException: Path property must be set before calling the Send method. Well, I thought I would maybe misunderstand the Methods that were provided by the page and I went back to my origina lCodeunit-Webservice excample. Unfortunately now I also get the same error as soon as I call the ShowData method that worked before.

My source code looks like this:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication2
{
    class Program
    {
        static void Main(string[] args)
        {
            testWS.TestWebService testWebservice = new testWS.TestWebService();
            testWebservice.UseDefaultCredentials = true;
            Console.WriteLine(testWebservice.ShowData("bla"));
                   
        }
    }
}

whereas testWS is my WebReference to that published Codeunit and ShowData of course the NAV-function.

I have not changed anything intentionally on the Marketing Demo. I already rebooted the machine, I restarted the Web-Service and republished the Codeunit in NAV - nothing helped.

Maybe someone has any idea?!

Thanks & regards
Jut