I'm not sure, but it seems like you have purchased a business class dsl connection from ATT and you are trying to use the five (or however many) publicly addressable IP addresses that came with that purchase and you have discovered that the only way to get that to work with your present network configuration is to manually assign those static values to the various network nodes.
Since ATT provides any number of various appliances to their customers I can not say exactly how to properly setup the network but if you provide the Manufacturer Name, Model Name, Model Number and Rev. Number or the appliance we may be able to help further. Without knowing this information we cannot know if it is capable of DHCP, however a support call to ATT might help you provision the device properly. Additionally it would be nice to know if you have any additional appliances, switches, hubs, and or routers included in your present configuration.
Ideally, I would suggest picking up a second router that fits your needs (wired or wireless or combo) add your username and password (if required ATT PPPoE) to the WAN side of this router and connect your ATT appliance to the WAN port of this router and connect your actual computers to the LAN side of this router and return your computer to AUTO for DHCP information.
EDIT: And yes, you will need to reconfigure the static addressing to auto if you take you computer elsewhere and expect it to connect to another network.