The PC is using DHCP.
I looked at the arp table and sure enough the IP address in question was listed with the MAC address. I found a IEEE search online via MAC address and the result was "Nortel" as the manufacturer. Our phone system is a Nortel SL1. I pretty sure we will find the IP address assigned to the Nortel in some fashion. When I ping the IP address I dont get a response when her PC is unplugged. The conflict only happens accasionaly.

Thanks for all your help on this.