Drahken, Not able to offer any help since I'm experiencing almost the same issues.
After having just replaced my PDC with a nice new shinny number I can't get the Internet routing working.
The 2k AD Server seems to be set up fine with DNS,DHCP all upp and running serving clients quite happily. Apart from routing to the DSL swith/router (DLINK 604+).
I've set up the DHCP scope options with the default gateway of the Router IP. However the only machine which will connect to the internet is the server. Which is obviously manually configured Static data in the Network TCP/IP properties.
A quick IPconfig of all client machines show the expected details but no conection.
Have you got anyway with the routing? Or can anybody else offer any hints?