No no, of course not. I was just giving the most likely error.
Also, the form tag itself doesn't specify a METHOD to send the form. For compatibility's sake, I would strongly recommend setting this method. The 'GET' method just encodes the form elements and adds them onto the URL in the query string. The 'POST' method does not add anything to the URL, but instead sends the form data via the HTTP headers sent to the server.
EDIT: Just confirmed this after doing some tests... I'm 99% sure of the problem. On the first server, register_globals is enabled. On the second, it is not. Use the superglobals (see the man page for [man]variables.predefined[/man] for more info) to access data sent via the GET/POST/etc. methods.