title: openx 2.8.1 "Session ID is invalid" when using XMLRPC api + ruby openx gem
body: <p>Occasionally when accessing OpenX 2.8.1 via its XMLRPC api (using the ruby 'openx' gem), I will get this error message:</p>
  
  <blockquote>
    <p>Session ID is invalid</p>
  </blockquote>
  
  <p>I cannot find anything in OpenX's forums about this, nor via some Google searching.</p>
  
  <p>I am starting to suspect that it is a bug or other issue in the ruby gem itself.</p>
  
  <p>Has anyone else encountered such an error, and if so, what is the fix? It <em>does</em> seem to resolve itself after running OpenX's maintenance scripts.</p>