Lean, i was trying to get at whether or not the serialization was failing, or if you literally didn't want the properties packaged when the object is serialized and sent.
If you are getting a equivalent of a null reference, or object not set to an instance, then you have a problem with a property not being initialized first, usually fixed with a "= New String(String.Empty)"
If you dont want the property to be packaged up then you should probably set the property to an equivalent of NOT SERIALIZABLE, so that it won't get packaged. If you don't want it to get packaged only some of the time then i would have to suggest you reconsider what you are trying to do, because i dont believe you can get a property set of conditionally serializable.
-The answer to your problem may not be the answer to your question.