title: Multiple periodically_call_remote calls not behaving as expected
body: <p>I've been doing ruby and rails for a long time but am a newbie when it comes to the more dynamic elements (currently jrails and jQuery), so it's entirely possible I'm missing something.  </p>
  
  <p>That said, I've got a page where multiple elements need updating from multiple sources.  For example, a dynamic header comes from one source and 5-6 divs of information come from the second.  I've got 6-7 periodically_call_remote calls with appropriate :condition flags set so only the visible one actually results in a call.  The problem is, even with none of the other divs visible, there are 7 calls to the dynamic header!</p>
  
  <p>For clarity, I created a page that demonstrates similar behavior:</p>
  
  <pre><code>&lt;%= javascript_include_tag 'jquery' %&gt;
  The server time is:
  &lt;%= render :partial =&gt; 'time' %&gt;
  &lt;%= periodically_call_remote(:update =&gt; 'time',
      :url =&gt; { :action =&gt; :time },
      :frequency =&gt; 3) %&gt;.
  
  Here's the results from some other function!
  &lt;%= render :partial =&gt; 'count' %&gt;
  &lt;%= periodically_call_remote(:update =&gt; 'count',
      :url =&gt; { :action =&gt; :count },
      :frequency =&gt; 3,
      :condition =&gt; "false")
  %&gt;
  </code></pre>
  
  <p>I'm expecting that, every three seconds, this will call 'time' on the server and replace the old 'time' div with the new one.  It'll never call 'count'.</p>
  
  <p>What actually happens is that, every three seconds, it calls 'time' <em>twice</em>.  If I include a third periodically_call_remote, it'll call it three times.</p>
  
  <p>Is this a bug?  A subtlety of jQuery I don't yet understand?  Ancient curse?  What's the deal here?</p>