Session State Question

I plan to use both application and session state items in an app I'm working on. Before I design too much I was playing with some simple code to get a feel for how this works.

The code I've posted below contains both a simple web service (Engine) and a C# console app client that uses the web service (Class1).

When I access the web service in a browser by typing the following url:

http://localhost/StateTesterWebService/Engine.asmx

all three web methods work fine.

However, when I run the console app containing the Class1 code below the program bombs on the following statement:

sessionVal = eng.Service2( );

I would think if there is a problem with the web service accessing it from both the browser and client app would bomb. Can any one explain

using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Diagnostics;
using System.Web;
using System.Web.Services;

namespace StateTesterWebService
{
public class Engine : System.Web.Services.WebService
{

private int baseValue = 5;

public Engine()
{
//CODEGEN: This call is required by the ASP.NET Web Services Designer
InitializeComponent();

SimulatedDBConnection dbConn = new SimulatedDBConnection( );
Application["DatabaseConnection"] = dbConn;
}

#region Component Designer generated code

//Required by the Web Services Designer
private IContainer components = null;

/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeComponent()
{
}

/// <summary>
/// Clean up any resources being used.
/// </summary>
protected override void Dispose( bool disposing )
{
if(disposing && components != null)
{
components.Dispose();
}
base.Dispose(disposing);
}

#endregion

[WebMethod(EnableSession=true)]
public void Service1( int incrementBaseBy )
{
// Service 1 will be used to demonstrate setting session state functionality
Session["SessionValue"] = baseValue + incrementBaseBy;
}

[WebMethod(EnableSession=true)]
public int Service2( )
{
// Service 2 will be used to demonstrate getting session state functionality
return (int)Session["SessionValue"];
}

[WebMethod]
public string Service3( )
{
// Service 3 will be used to demonstrate getting application state functionality
SimulatedDBConnection dbConn = (SimulatedDBConnection)Application["DatabaseConnection"];
return dbConn.GetConnectionMessage( );
}
}
}

using System;
using StateTesterClient1.StateTesterWebService;

namespace StateTesterClient1
{
class Class1
{
[STAThread]
static void Main(string[] args)
{
Engine eng = new Engine( );

int sessionVal;

Console.WriteLine( eng.Service3( ) );

eng.Service1( 5 );
sessionVal = eng.Service2( );
Console.WriteLine( "Client 1 Session state variable is: " + sessionVal );
}
}
}