This *sounds* like the DHCP client in the DAR getting upset with the DHCP server on your network. Try putting autoconfiguration on (enables the DAR server's DHCP server) and disconnecting the cable modem/router from the network to see if it works then. If it does, then the problem is the DHCP client (we've heard of another case of this recently too).

Can you tell me what make/model/version-nr your cable/dsl router box is?

Hugo