NSManagedObject - relationship fault

NSManagedObject - relationship fault

I have two entities correlated (E1,E2) with a one to many relationship E1
<--->> E2 (relationship name: pictures)
E1 also has other relationships one to many with different Entities (E3,E4)
When I retrieve the E1 from coredata E1.pictures result:
pictures = "<relationship fault: 0x1d5a8c60 'pictures'>";
Now,
I know that this kind of message is not an error :)
E1.pictures is not empty.
When I save a new picture and I provide to refresh the E1 managed object (
[E1.managedObjectContext refreshObject:E1 mergeChanges:YES]; ) the
E1.pictures is returned back correctly and I can show the images.
I try to make the refreshObject:E1 before to take the count, but it
doesn't work
I assume that I retrieved the object correctly. I would like to know
before save a new picture how many pictures have the E1 and obviously show
the pictures (but without a picture count... I don't go anywhere)
Could I be missing something? Can somebody help me?