Add new phone in Address Book

Hi all,
I’m trying to add a new phone to a person in Address Book and all it’s ok.
If I try to add a new phone with label of every kind and value “” (empty string) and then
I synchronize this contact with my PDA I have an exception opening this contact on the PDA because
the phone value is empty.
The exceptions says :
Fatal error
Empty field being added

How can I add a phone without value ?