title: Firefox "Bad request" caused by corrupt google tracking cookie
body: <p>We have an issue on our site whereby <em>some</em> Firefox users are receiving a "Bad Request" message when they visit our site (nothing else, just the words "Bad Request"!)</p>
  
  <p>This would appear to be due to a corrupt google tracking cookie, possibly <code>__utmz</code> (one person delete the google cookies in turn and once that one was removed the site came back to life.)</p>
  
  <p>Our website uses this Javascript google tracking code:</p>
  
  <pre><code>    var gaJsHost = (("https:" == document.location.protocol) ? "https://ssl." : "http://www.");
      document.write(unescape("%3Cscript src='" + gaJsHost + "google-analytics.com/ga.js' type='text/javascript'%3E%3C/script%3E"));
  
      try {
          var pageTracker = _gat._getTracker("UA-**********");
          pageTracker._trackPageview();
      } catch(err) {}
  </code></pre>
  
  <p>Occasionally we also use this to create a different pseudo-URL to track in google analytics when  a form has been completed:</p>
  
  <pre><code>  pageTracker._trackPageview('{$smarty.const.CONST_PAGE_URL}/complete');
  </code></pre>
  
  <p><code>{$smarty.const.CONST_PAGE_URL}</code> is just a bit of template code to output the real, current page url.</p>
  
  <p>Finally, probably not relevant but, for cross tracking in our CRM, we also use Salesforce tracking loaded from <a href="https://lct.salesforce.com/sfga.js" rel="nofollow noreferrer">https://lct.salesforce.com/sfga.js</a> which  is kicked off from Javascript in our page footer like this:</p>
  
  <pre><code>__sfga();
  </code></pre>
  
  <p>I have had a report of this issue from a user of Firefox 3.5.7 - I don't know about the others (except they were using Firefox).  Does anyone know what might cause this and if there is any way to stop/avoid it?</p>
  
  <p>Many thanks - BTW stack overflow rocks I use it often :O)</p>
  
  <p>Ben</p>