Need help troubleshooting log messages

[Timothy Holtzen]

Hi all.  I'm somewhat new to ISC dhcp and don't quite know what to make of some messages I'm getting in my logs:

uid lease 10.12.1.165 for client 00:17:f2:dc:c5:41 is duplicate on 10.12/16: 1 Time(s)
uid lease 10.12.1.198 for client 00:17:f2:e0:4d:a5 is duplicate on 10.12/16: 1 Time(s)
uid lease 10.12.2.192 for client 00:17:f2:dc:c5:41 is duplicate on 10.12/16: 1 Time(s)
uid lease 10.17.1.161 for client 00:1b:63:1e:ac:49 is duplicate on 10.17/16: 1 Time(s)
uid lease 10.17.1.99 for client 00:1b:63:1e:ac:49 is duplicate on 10.17/16: 1 Time(s)

Googling about it would appear that these messages are usually the result of a misconfiguration of the server when  overlapping pools are setup or a host entry is setup with an IP number within a pool.   I've double checked that my pools for these subnets don't overlap and none of these clients is listed in any host entry.  Does anyone know what might be causing these messages or how I might go about troubleshooting them?  I tracked down the first client listed and it doesn't appear to be having any problems with IP conflicts or the like.  It does however appear over time that the client gets the IP 10.12.2.192 for a while and uses it and then gets the IP 10.12.1.165 and uses it for a while but not both at the same time.  Could it be these clients are simply requesting a new lease each time rather than renewing their existing one?  If so why would they do that?  Any help would be appreciated even if you can just point me at the right documentation or web site posting. 

I'm running dhcp-3.0.5-7.el5 under RHEL 5.

-- 
Timothy A. Holtzen
Campus Network Administrator
Nebraska Wesleyan University