Novell DNS will take DDNS updates from Windows just fine. You just have to be properly configured. Make sure that the same primary DNS server is assigned to both the forward and reverse zones. Make sure that under your control lists you have the DHCP server listed under "allow updates". Assuming you aren't doing TSIG keys or anything, then it should be working fine. You can tailf /var/log/messages or /var/opt/novell/named/ and watch DDNS updates come in. If it fails you will get a message as to why. I have setup DDNS between windows and Novell products in the past without issue.