title: Core Data multi thread application
body: <p>I'm trying to use core data in a multi thread way.
  I simply want to show the application with the previously downloaded data while downloading new data in background. 
  This should let the user access the application during update process.</p>
  
  <p>I have a NSURLConnection which download the file asyncronously using delegate (and showing the progress), then i use an XMLParser to parse the new data and create new NSManagedObjects in a separate context, with its own persistentStore and using a separate thread.</p>
  
  <p>The problem is that creating new objects in the same context of the old one while showing it can throws BAD_INSTRUCTION exception. 
  So, I decided to use a separate context for the new data, but I can't figure out a way to move all the objects to the other context once finished.</p>
  
  <p>Paolo aka SlowTree</p>