Hi,
unfortunatelly Doctrine2 does not support behaviors and thats why ORM Designer will not allow you to set them up. Behaviors were only supported in the original Doctrine.
In case you are using the Gedmo extension with Doctrine2, it is a third-party extension and it is not supported by ORM Designer at the moment. We consider implementing support for Gedmo in the future, but at this time it is necessary to write Gedmo annotations manually. However ORM Designer will not delete or modify these annotations so you can combine the two without problems.
Martin