Ignore the warning if the Updater complains that PostgreSQL is too new when you log in. Pay attention to the warning if it's part of a prerequisite check after opening a .gz file or if it says that a PostgreSQL version is too old (e.g. "version 8.2 isn't supported").
The Updater itself doesn't do much. Mostly it's a wrapper around what the .gz files tell it to do. That's why the prerequisite check failures are important. Version 2.5.2 is less picky about PostgreSQL versions.