Thomas,

I am using version 1.1.  I retested the code and I am still having the problem.  I capture the network trace this time.

When run as a browser control the http request is formatted as follows:
GET /test.asp?te/st HTTP/1.1
Connection: Keep-Alive
Host: localhost:8080

When run as a stand alone app the http request is formatted as follows:
GET /test.asp?te\st HTTP/1.1
Accept: */*
User-Agent: Mozilla/4.0 (compatible; MSIE 4.01; Windows NT)
Host: localhost:8080
Connection: Keep-Alive

Again in both cases I used the following code:

import java.applet.Applet;
import java.applet.AppletContext;
import java.awt.*;
import java.net.URL;
import java.net.*;
import java.io.*;

public class AppletTest extends Applet
{
  private void connect()
  {
     this.add(new Label("test"));
     try
     {
        URL url = new URL("http://localhost:8080/test.asp?te\\st");
        URLConnection conn = url.openConnection();
        InputStream in = conn.getInputStream();
        in.close();
     }
     catch (Exception e)
     {
        this.add(new Label(e.getMessage()));
        e.printStackTrace();
     }
  }

  public void start()
  {
     connect();
  }
}

Here is the code for the stand alone app:

package AppletTestDriver;

/**
* Summary description for Class1.
*/
public class Class1
{
    public Class1()
    {
        //
        // TODO: Add Constructor Logic here
        //
    }

    /** @attribute System.STAThread() */
    public static void main(String[] args)
    {
        AppletTest applet = new AppletTest();
        applet.start();
    }
}