Indeed the installation checks whether there is already an existing cluster on port 5432. It tries the next port until it finds a free one.
** Changed in: postgresql-8.1 (Ubuntu) Status: Unconfirmed => Rejected -- By default server listens on 5433 https://launchpad.net/bugs/49043 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs