Another computer on this network has the same address. I wonder if it could be a computer I've retired? I am Chopters@earthlink.net. On several occasions I've received a note telling me to contact my network administrator on this topic.
Check the IP on the computers in your house/work/ whatever. When you find a duplicate, release and renew it's IP or change it if you are using a static IP. Rebooting your devices should clear this up also.