Desktop can not resolve IP to DNS name

I have a Windows XP Pro workstation on a small office network. We recently
changed out our router and a new IP address was assigned to our Server (used
to be 192.168.1.104 and it is now 192.168.3.104). All the Workstations on
the network use DHCP and have been successful resolving the DNS name to IP
address for the server...all except one. For some odd reason, we have one
workstation that continues to resolve the OLD IP address for the server to
the DNS name for the server; yet, I can ping the new Ip address AND I can use
drive mappings and lookup the server in Network Places and locate it with its
DNS name. It appears that this workstation will not give up the old IP
address.

I've used ipconfig /flushdns
I've checked the server and all the other workstations and they are all
consistent. And, as I said, the other workstation when I ping the SERVER
Name resolves to the proper IP address. So, I'm thinking it's a PC problem
BUT what in the PC would hold on to the OLD IP address for the server name?

Thanks