We have a very mixed network, with most clients being Debian Lenny, the rest Windows XP/Vista/7. The network itself is split into two segments (for technical reasons) called "corporate" and "engineering". On the "corporate" side all clients get their IP addresses from a Windows DHCP server and the dynamic updates into the Windows DNS work just fine. On the "engineering" side, clients get their IP addresses from a linux machine running the standard ISC DHCP server. Although this server is configured to do dynamic DNS updates, they actually don't work. Anybody got any advice on how to fix this?

Please note: dynamic updates from the clients directly into the DNS would work, but are not an option for us. So this is strictly on how make this work from an ISC DHCP server to a Windows DNS server.