title: Query Notification Error
body: <p>We have this weird issue regarding SQL Query Notification service. 
  We have a main web application running with QN service so the cache item in the web get notification from SQL when the monitoring data changed. And it runs well. 
     What is weird is when the other supporting web service tries to register QN subscription into SQL 2005 SP2 and this error occurs </p>
  
  <p>"System Exception: SqlDependency.Start has been called for the server the command is executing against more than once, but there is no matching server/user/database Start() call for current command " </p>
  
  <p>This error only happen when SQL query in SQLDependency against particular instance DB. The other instance DB works just fine. </p>
  
  <p>There are not much resource can be found for QN / service broker issues. Wish anyone has similar experience can share their knowledge.  </p>