Before a server starts up, we do one "poll" against it, basically to see if an instance is already running. If an instance is already running (either launched outside or eclipse or somehow was never shutdown), we present the user some options on how to handle this... such as launch anyway, or cancel since a server is already up.
To perform this poll, we use the poller you have selected in the server editor. It would appear that attempting a management connection to a nonexistant server takes longer to timeout than making a web connection.