You should never have two machines on the same network with the same IP address. You may encounter trouble with lost packets and dropped connections later on if you continue to use your machine in this configuration.
Normally, if any computer has the same IP address as a host on the network the host will shut down the connection. The first release of Open Transport in System 7.5.2 did not check to see if there was a duplicate IP address and therefore would not present you with a warning or dialog that the condition existed.
This issue has been resolved. You should update to Open Transport 1.1 or newer.