title: NSFetchedResultsController "out of order section name'
body: <p>I'm using <code>MagicalRecord</code> to fetch my data. In my app I have a list of contact that are grouped into contact groups. I am displaying these contact groups in a grouped <code>UITableView</code>.</p>
  
  <p>For example, I have the following (which is what I expect):</p>
  
  <pre class="lang-m prettyprint-override"><code>Default Groups  // section header
  [Everyone]      // cell row
  [Favourites]    // cell row
  
  My Group        // section header
  [Coworkers]     // cell row
  </code></pre>
  
  <p>Sometimes my groups get mixed up:</p>
  
  <pre class="lang-m prettyprint-override"><code>Default Groups  // section header
  [Everyone]      // cell row
  [Coworkers]     // cell row
  
  My Group        // section header
  [Favourites]    // cell row
  </code></pre>
  
  <p>Each Contact group name and group type that I use to sort and group by. Group type is an integer. When I check their attributes they do in fact have the correct group type.</p>
  
  <p>My FRC looks like this:</p>
  
  <pre class="lang-m prettyprint-override"><code>fetchedResultsController = [ContactGroup fetchAllSortedBy:@"groupName"
                                                  ascending:YES
                                              withPredicate:nil
                                                    groupBy:@"groupType"
                                                   delegate:self];
  </code></pre>
  
  <p>I see the following error:</p>
  
  <pre class="lang-m prettyprint-override"><code>CoreData: error: (NSFetchedResultsController) The fetched object at index 2 has an out of order section name '1. Objects must be sorted by section name'
  +[MagicalRecord(ErrorHandling) defaultErrorHandler:](0x2eefb8) Error: The fetched object at index 2 has an out of order section name '1. Objects must be sorted by section name'
  +[MagicalRecord(ErrorHandling) defaultErrorHandler:](0x2eefb8) Error Message: The operation couldn’t be completed. (Cocoa error 134060.)
  +[MagicalRecord(ErrorHandling) defaultErrorHandler:](0x2eefb8) Error Domain: NSCocoaErrorDomain
  +[MagicalRecord(ErrorHandling) defaultErrorHandler:](0x2eefb8) Recovery Suggestion: (null)
  </code></pre>
  
  <p>Please let me know if I need to provide more details, I am kind of stumped at this point and not 100% sure what to do.</p>