Snow Leopard Server, Big Problems with Networking

I have two large posts on two other forums, so I'll get right to the point here. I tried upgrading my Mac Mini from 10.5 server to 10.6 server. On 10.6, my server was not able to get an ip from DHCP. After 2 days of messing around, I went back to 10.5 and everything worked perfectly. Well in the process of doing this, my MacBook Pro, which had been running 10.6 Server since about day one, well now it also can't get an IP over DHCP. Only difference is that the MBP CAN get an ip over ethernet, it just can't get an IP over Airport. The mini couldn't' get an ip over built in etherhet, or the apple usb ethernet. Well the mini is back to 10.5 and thats fine for now. But the Macbook is what I use for work (its running server solely for the netboot server). I need it fixed. I tried every trick in the book, nothing was able to get my mini to work for more than an hour or so. Then all on it's own, it would drop it's IP and go to self-assigned, and it would never, EVER get another IP again. Thats kind of what my MacBook is doing. The only way I can have it get an IP over AirPort, is to netboot the machine off a 10.5 disk image. Then it gets an ip over airport right away, but that's not very helpful. So is anyone else having these major DHCP [i]CLIENT[/i] problems with 10.6? And of course, does anyone know a solution?