I have been going back and reading through a lot of the SRNDs and configuration guides to refresh everything that I have been going over in my lab. I came across one very interesting tidbit of information that I must have glanced over before regarding CUE and configuring the service-engine to reference the loopback interface.
In all of my practice labs from IPExpert, you are always instructed to use the voice VLAN for the CUE module. So, using the ip unnumbered VLAN 400 command does not pose any problems. However, when I attempted to issue this same command, but swapping Loopback 0 for VLAN 400, the router started throwing all sorts of errors. I was able to session into the module, however it did not have any IP connectivity outside of the local router.