DNS Server not adding clients from DHCP?

I come from a Windows background, but just got handed an Xserve running Snow Leopard Server. I need to set it up as DHCP and DNS... I followed what appeared to be a pretty detailed guide and everything is working per se, but I am not seeing clients added to the Primary DNS zone?

The issue is I have 4 or 5 DHCP scopes for different subnets (192.168.1.0, 192.168.2.0, etc...) and since bonjour doesn't appear to easily be routable, I wish for my clients in one subnet, to be able to type in "machine_name.domain.com" to access another clients machine (we do web stuff, everyone is running webservers on their machines). This is easier than getting up, asking their neighbor what their IP is, and then remembering that to type in there browser - only to have it change the very next day...

With Windows Server, any clients receiving DHCP addresses automagically get added to DNS.

I'm not complaining - just wondering A.) If they are supposed to be showing up, and B.) Why they aren't (might have something to do with Bonjour?), and C.) If it's not possible - what are others using as a solution to this???

Thanks!