sqlnet v2 - non-unique name error on reboot

On a Sol2 Ora7.2 setup, every time the LISTENER is run after reboot, it complains that the (db?) names are non-unique on the network.

Editing the connect aliases in tnsnames.ora and listener.ora fixes this. But next reboot ... and the same complaint. Eg sqlplus scott/tiger_at_mydb1 could become sqlplus scott/tiger_at_mydb2. The listener is usually not stopped for a reboot (...it will be in future!).

BUT, the set of network/admin files - listener.ora, tnsnames.ora and sqlnet.ora were copied from a SunOS setup (7.1.6 rdbms) - which doesn't show this problem. Listener starts up fine every time. These files were edited on the new Sol2 box to change host names , oracle home directories and, of course, the aliases. But not the key string in sqlnet.ora (could this be conflicting with the SunOS box on the same network?).

Any ideas? (apart from an automatic random name generator)

Cheers

        Gary Walker