Connect port x4 lost association with CC2530-based end devices after coordinator lost power!

We have designed an end-device and router using the cc2530 from TI. We are using the digi connect port x4 as coordinator.

The system came up fine when first turned on. Later on, the coordinator lost power. After repowering up, the network coordinator lost all associations with the end devices. It could see the routers but none of the end points.

What stupid thing have we overlooked that would cause the coordinator to lose the end devices? We had to physically go to the location and restart the EDs before the network would recognize them.