What would happen?? I used "import" and "useBean" for same bean...

Question

Hi, yes, I'm not a professional programmer (clearly)
I used the import page directive and the jsp:useBean statement for the same bean in a jsp program I wrote.
What's interesting is that the program works fine for me, storing values and retrieving them from the bean as I click through the different jsp pages.
However, it doesn't work well for one of my friends, the values usually get lost as he clicks through the jsp pages.
I then noticed I used both statements to refer to the same bean, is that why this is happening? Were two instances of the bean sometimes being created even though the useBean had scope = session?
Something else, again, the program works perfect for me, not for him. We did a speed check using:
http://helpme.att.net/dsl/speedtest/
His speed was twice as fast as mine. Would that explain why he sometimes (almost always actually) lost values between the jsp pages?
Below is the first few lines on each jsp page:
<%@ page language="java" import="java.util.*" %>
<%@ page errorPage="exception.jsp" %>
<%@ page import="test1.UserData"%>
<jsp:useBean id="user" class="test1.UserData" scope="session"/>
<jsp:setProperty name="user" property="*"/>
Thanks for any and all help,
Robert

Answer 1

The webcontainer creates a new cookie for each session so that it can keep track of each user session. If cookies are disabled, then sessions are been tracked by URL rewriting (a query parameter 'jsessionid' will be attached to the URL with the session ID as value).
Opening a new browser instance (not a tab or a new window from within the currently running instance) would also trigger a new session being created.