No more "white-out" problem. The solution was to replace my old VR31A 2.4 GHz Wireless Audio/Video Receiver with a new VR42A 2.4 GHz Wireless Audio/Video Receiver. With the new Receiver both old (XX11A) and new (XX18A) cameras work fine. If I revert back and use my old Receiver the old cameras work fine, but the new cameras exhibit the "white-out" condition.
X10 (the Company) was unable to offer an explanation on why the XX18A camera image is washed out with the old Receiver. X10 has said, I was "the only customer who has contacted them with this specific problem."
jelester and jflynn -- if you find that you have the old VR31A receiver and your new cameras have "white-out", the Receiver could be the problem. Contact X10 and tell them your symptoms.