[Neos] Two prototypes siblings of same prototype with different resutlts?

[Carsten Bleicker]

hi,

prototype(BLEICKER.SavingDogs:AbstractAnimalList) < prototype(TYPO3.Neos:Content){
	animals = ${q(site).find('[instanceof BLEICKER.SavingDogs:AbstractAnimal]')}
	animalListItem = BLEICKER.SavingDogs:AnimalListItem
}

// This one works
prototype(BLEICKER.SavingDogs:AnimalList) < prototype(BLEICKER.SavingDogs:AbstractAnimalList){

}

// This one is empty????
prototype(BLEICKER.SavingDogs:EmergencyAnimalList) < prototype(BLEICKER.SavingDogs:AbstractAnimalList){

}

why the 2. and 3. list having different behaviours?
any ideas?