PingPlotter uses standard Windows API (ie: Winsock) calls to resolve an IP address into a DNS name. This is the same method that most Windows applications use.

If you ping these IP Addresses (using the command line PING utility) from the different machines, you should see similar inconsistencies between the two machines.

The API calls used to do this lookup *certainly* use the machine's DNS server settings to determine how to resolve these IP addresses into names.

NSLookup *might* also show the same thing, although NSLookup uses a different mechanism to do the name lookups. It might be helpful for you to check out NSLookup and see what name servers are being used on the different machines.

You should also know that a single IP address can resolve to numerous names. PingPlotter shows only the first name in the list in the DNS name column, so if different machines get the list in different orders, they might list different names from that list in PingPlotter.

- Pete