jvaliensi,
If you had connected the CRU to a CB200 servo port, not the Rex7, all would have been fine.
You had everything daisy-chained from the Rex 7, and with only 300mA available from the 2 C200 Rx ports, the door servos pushed you over the edge and they both blew, shutting both Rx's down.
I'm assuming that the previous setup with the JP controller, that it was connected directly to a CB servo port, or maybe the JP controller uses direct battery power for the servos.
Paul