MR_save seems to delete objects in context - ios

Question

I am using magical record to handle core data. I have code that creates a Entity which looks as follows:
if ( gameEntity == nil )
{
gameEntity = [GameEntity MR_createEntity];
}
gameEntity.opponent = opponent;
gameEntity.me = me;
etc...
When I then query for game entities as follows:
NSPredicate* gamePredicate = [NSPredicate predicateWithFormat:#"SELF IN %# AND gameState != %#", me.myGames, GAME_ENTITY_STATE__OTHER];
NSFetchRequest* fetchRequest = [GameEntity MR_requestAllWithPredicate:gamePredicate];
NSArray * results = [[NSManagedObjectContext MR_defaultContext] executeFetchRequest:fetchRequest error:nil];
return results;
Results has a size of 1 (which makes sense).
However when I save the context as follows:
[[NSManagedObjectContext MR_defaultContext] MR_save];
And run the same fetchRequest above, all of a sudden the GameEntity is gone and there are no results in NSArray.
Even weirder when I shut down the app and run it again, it finds the GameEntity. So it was in fact saved. Why is MR_save essentially breaking my NSManagedObject context?
All the save and creates are being run on the main thread.

Answer 1

So it turns out that the problem was my predicate, which makes this more of a CoreData problem than a magical record.
I changed the predicate from this:
NSPredicate* predicate = [NSPredicate predicateWithFormat:#"SELF IN %# AND gameState != %#", me.myGames, GAME_ENTITY_STATE__OTHER];
To this:
predicate = [NSPredicate predicateWithFormat:#"me == %# AND gameState != %#", me, GAME_ENTITY_STATE__OTHER];
For some reason the first predicate is not always accurate. While the second one seems to always work.
While this does answer the question, I'd be curious why people believe why the first predicate doesn't always work...