HELP - Socket and Hostname?

[lydia westland]

Hi all,
I used the InetAddress.getHostName() to get a computer's name. and the InetAddress.getIP(). The InetAddress is generated when the socket connection is established. But a werid thing is, sometimes this works well. sometimes the hostname is the IP( not the computer name). and sometimes the hostname can become some words got from the Hosts file. How can I do to make them consistent?
thank you.