[TYPO3-mvc] Own property-validator not working on edit/update

[Wolfgang Rock]

Hi list,

I have a simple validator for one of my model-properties, which works well in the new/create action.
But in the edit form, the validator is ignored and the object is safed.
Core-extbase-validators like notEmpty keep working...

The validator looks like this:
class Tx_Asbfunk_Domain_Validator_KennzahlValidator extends Tx_Extbase_Validation_Validator_AbstractValidator {
    /**
     * @return bool
     */
    public function isValid($value)
    {
         if(preg_match("/\d{2}-\d{3}/", $value)) {
            return true;
        } else {
            $this->addError('Die eingegebene Kennzahl hat nicht das korrekte Format!', 12321559976);
            return false;
        }
    }
}

I'm using it instead of core-regexp to customize the error-message.
TYPO3 4.6.0 with Extbase 1.4 with new property-mapper.

Any ideas?

Thanks and cheers,
Wolfgang