samba - Jun 2014 - Duplicate IP address for different Host A record / Internal DNS

Hello,

     Using Samba 4.1.7 on Ubuntu 12.04. It appears that I have duplicate 
Host A records with the same IP but with different host names. It looks 
as if when a host registers with an IP it doesn't delete or update the 
existing record. Is this a known issue or can I set the zone to scavenge 
stale records? I receive an error when attempting using the Microsoft 
DNS tools. I see in Samba log file " 
../source4/dns_server/dns_utils.c:282(dns_replace_records)  Deleting 
record failed; 50" I guess it's trying to delete the record but
failing?
Thanks.

-- 
-James