Regardless, it makes more sense to me to have my router serve static IP addresses to the WIUs, based on their MAC addresses. This way, the WIUs stay in factory setting mode.
I see where Barry is coming from here. However, there is a small advantage to Static IP's assigned on the WIU. There is no wait time for the DHCP process to occur between the WIU and your router. Also when you turn on your layout, 5 WIU's are no longer hammering the router for an IP address, it's already configured right out of the gate and decreases the boot up time of the WIU slightly.