We'll probably need some more information to figure this out, but it sounds like the third installation is trying to use the same db as the first one. Is the third installation configured to use "kg" as its db? Do you see any error messages in the log file of the third installation? Do you see any messages like:
"Ns_PgOpenDb(postgres): Openned connection to localhost::yourdbname"
in the log file of the third installation? Where yourdbname is the name of the db that your third installation is connected to.
