What does your SMP say under Network Settings for IP address, netmask, gateway, and DNS server?
Goto: Setup > Network Settings > Network Setup
What about Check Connection? (I am not clear on when you are getting a DNS error from the SMP.)
(There certainly are network devices around that do not properly adhere to DHCP, but you should be able to bypass DHCP problems by manually overriding invalid settings.)
What is the IP address of the router and the netmask you have set on it? If this doesn’t match the SMP won’t work.
(You certain no other device on the network has the same IP address as the SMP? If two devices share IP then your network won’t function properly. Very easy to screw this up if you are manually setting IP addresses.)
If the DNS server address on the SMP is the router’s IP address, then are you sure the router is setup to act as a DNS relay?
What DNS server address is being used by your PC?
You sure you do not have some kind of blocking setup on the router? There can be several ways this might happen.
Does your router have a way to see devices on your network or that have been given IP addresses via DHCP? If so, if the SMP listed?
First gather and post the info I asked for.
While waiting for responses, here is what I would try: turn off (pull power to) every network device except your cable modem. Then turn on the router. Now turn on only the SMP. Make sure there is still a problem.
