I have an iMac that keeps displaying the message "Another device on the network is using your computer's IP address". Here's how the problem started: "IMac A" was set up with a static IP address of 10.10.10.10 but was having hardware/software issues (kernel panics, freezing, etc). I copied all the user files to a new iMac and then set up the new iMac (iMac B) with a static mapped IP address of 10.10.10.10 from snow leopard server using DHCP. I removed iMac A from the network to do some troubleshooting and try to figure out what was wrong with it. Then I formatted the hard drive, reinstalled snow leopard, and plugged it back into the network. With the network configuration set to "Using DHCP", it keeps trying to get the 10.10.10.10 address again, which of course conflicts with iMac B. In DHCP Server Admin, there are no leases listed for iMac A. If I add a static DHCP mapping for a different address, everything is okay, but as soon as I remove the static mapping it tries to go back to the 10.10.10.10 address! Any help would be appreciated.