Cannot access with modifier error.

I get this error when I try to instantiate the class coded below. Can
anybody help.

IllegalAccessException: Class
koala.dynamicjava.interpreter.context.GlobalContext can not access a
member of class url.DnldURL with modifiers ""
  at sun.reflect.Reflection.ensureMemberAccess(Unknown Source)
  at java.lang.reflect.Constructor.newInstance(Unknown Source)

package url;

import java.io.*;
import java.net.*;

public class DnldURL {
    private DataInputStream URLData;

    DnldURL() throws IOException {

        try {
            URLData = new DataInputStream(new BufferedInputStream(
                new URL("someurl.com" ).openStream()));

        }
        catch (MalformedURLException mue) {
            System.out.println("Ouch - a MalformedURLException
happened.");
            mue.printStackTrace();
            System.exit(1);
        }
    }

//_________________________________________________________________________________

    public DataInputStream getURLData() {
        return URLData;
    }
}