Really frustrating DNS problem

[sidewinder]

Ok, so I had a computer in one location, it received an IP address for that subnet. I then moved it to another location, it correctly received an IP from that subnet.

 

The issue is, the DNS servers still have the old address on the A record. So DHCP automatic updates are not working right? Perhaps, but even if I do a manual update from the machine, and then verify that the record has been updated, a few hours later it is back to the old IP address again. I'm fairly sure every time I have checked all 4 of our DNS servers (2 at main site, 1 each at secondary sites) the record has updated on all, but something is bringing the old one back.

 

Surely once a client has updated it's own DNS record, no other server should be able to overwrite that? Since even if the old record was present, the timestamp would be older than what was updated?

 

We haven't made any DNS changes recently, all the servers have been in place for years. There are no replication errors logged and zone transfers & dynamic updates are setup. Even just for this one machine it's a nightmare since our Fortigate firewall stops authenticating since it can't contact the host and this user then receives the fallback most restrictive web filtering. I'm also worried it's indicative of a larger problem that hasn't reared it's head yet.

 

Any ideas?