Dynamic DNS

[Bind Bind]

I am trying to setup Dynamic DNS for our internal nameservers, but I am
confused....  Do the A records ever expire or get removed out of the
nameservers cache?
For example, I had a host register "host01", then changed the name of the
machine, rebooted, and it registered the new name "host02" into dns, however
it did not remove the host01 entry (they both point to the same IP).

I am also getting this error:

Sep 13 11:22:23 ns01 named[155]: error processing update packet (NXRRSET) id
11 from [64.28.75.25].1058

The dynamic updates are coming from Win2k DDNS in the TCP/IP properties...
Can someone shed some light on this anomaly?
-Arthur D'Alessandro
adalessandro at odione.com