title: Register events of multiple objects using DispEventAdvise
body: <p>I have a class that inherits from "DispEventAdvise" (for outlook2010, but its not important):</p>
  
  <pre><code>class item_2010_event_handler : 
  public IDispEventSimpleImpl&lt;IDC_OUTLOOK_ITEM_2010_EVENTS, 
                              item_2010_event_handler, 
                              &amp;outlook_item_2010_ev_id&gt;
  </code></pre>
  
  <p>Now, I want to register a single instance of item_2010_event_handler to get events from multiple objects, so I call DispEventAdvise() multiple times (once for each object), but from the 2nd time I call DispEventAdvise() I get "Unknown Error" exception from the function.</p>
  
  <p>Is it possible it is not supported? and if not, why not???</p>
  
  <p>If it is possible, what am I missing (obviously I'll add more code if it is needed...)?</p>