title: error in entlib 6 logger instantiation
body: <p>I am getting an exception while setting the logwriter for Enterprise Library 6.0 logging component. On the first occurrence of logging, it succeeds. But for the consecutive calls it throws an exception: <code>The LogWriter is already set.</code> I have tried with checking if the Logger.Writer is not null. But this fails in the first instance, with an exception that I should set the writer using Logger.SetLogWriter.</p>
  
  <p>Here is my code:</p>
  
  <pre><code>if (Logger.Writer == null)  // fails on first call
  {
      IConfigurationSource configurationSource = ConfigurationSourceFactory.Create();
      LogWriterFactory logWriterFactory = new LogWriterFactory(configurationSource);
      Logger.SetLogWriter(logWriterFactory.Create()); // fails on subsequent calls.
  }
  </code></pre>