title: NSPredicate on Magicalrecord retrieves old results
body: <p>I dont know how this is happening, but I have a fairly complex NSPredicate:</p>
  
  <pre><code>NSString rentalStatus = @"Available";
  [NSPredicate predicateWithFormat:@"(status != nil) AND (status == %@)", rentalStatus]
  </code></pre>
  
  <p>I then search with:</p>
  
  <pre><code>rentals = [RegisterSaleRental findAllSortedBy:@"rental_due_date" ascending:NO withPredicate:predicate];
  </code></pre>
  
  <p>Everything is fine, but if I quickly set a status from Available to Rented, the objects shows as Rented on the screen (so the status is set) but when I try to filter for Rented:</p>
  
  <pre><code>NSString rentalStatus = @"Rented";
  [NSPredicate predicateWithFormat:@"(status != nil) AND (status == %@)", rentalStatus]
  </code></pre>
  
  <p>It doesnt show the object I just set to Rented :( If I filter for Available again it does show up, but the status I get in the object in the result it Rented, so it basically searches trough old data.</p>
  
  <p>When I save core data with:</p>
  
  <pre><code>[[NSManagedObjectContext defaultContext] saveToPersistentStoreAndWait];
  </code></pre>
  
  <p>It does, and works perfectly fine.
  My question is do I have to save everytime before I change the status or anything? I cannot find anywhere that this is needed. Thanks!</p>
  
  <p>Update (core data setup code)</p>
  
  <pre><code>// Configure MagicalRecord to use RestKit's Core Data stack
      [NSPersistentStoreCoordinator MR_setDefaultStoreCoordinator:managedObjectStore.persistentStoreCoordinator];
      [NSManagedObjectContext MR_setRootSavingContext:managedObjectStore.persistentStoreManagedObjectContext];
      [NSManagedObjectContext MR_setDefaultContext:managedObjectStore.mainQueueManagedObjectContext];
  </code></pre>