title: Selenium cannot set preference for browser.link.open_newwindow
body: <p>I'm using Selenium to test my website, normally when i do "profile.setPreference("browser.link.open_newwindow", 1)" i got no problem with it. However, when i try to move everything into a function inside a class, as below:</p>
  
  <pre><code>private FirefoxProfile _ffp;
  private WebDriver _driver;
  private UserAgentList _userAgentList;
  ....
  public void initializeProtocol(){
      this._ffp = new FirefoxProfile();
      this._userAgentList = new UserAgentList();
      setUserAgent();
      this._ffp.setPreference("permissions.default.image", 2);
      this._ffp.setPreference("browser.link.open_newwindow", 1);
      this._driver = new FirefoxDriver(_ffp);
  }
  </code></pre>
  
  <p>I got this massage when i change the value to 1, (2 works fine):</p>
  
  <blockquote>
    <p>Exception in thread "main" java.lang.IllegalArgumentException:
    Preference browser.link.open_newwindow may not be overridden: frozen
    value=2, requested value=1</p>
  </blockquote>
  
  <p>I've been trying to figure out whats wrong but seem like i cannot be able to. Please help. Thank you so much,</p>