JNDI: DirContext::list throws on exception when existing context is in LDAP

Question

I was able to import tutorial.ldif using LDAP Browser/Editor without incident:
http://www-unix.mcs.anl.gov/~gawor/ldap/
My LDAP now has the following tree:
o=JNDITutorial
ou=Groups
5 cn entries
ou=People
10+ cn entries
However, when calling DirContext::list("ou=People"), it throws the following exception message:
javax.naming.NameNotFoundException: [LDAP: error code 32 - No Such Object]; remaining name 'ou=People'
Here is the code:
     final static String ldapServerName = "backbone.seamonkey";
    public static void main(String[] args) {
     // Set up the environment for creating the initial context
     Hashtable env = new Hashtable(11);
     env.put(Context.INITIAL_CONTEXT_FACTORY, "com.sun.jndi.ldap.LdapCtxFactory");
     env.put(Context.PROVIDER_URL, "ldap://" + ldapServerName +"/o=JNDITutorial");
     try {
         // Create initial context
         DirContext ctx = new InitialDirContext(env);
         // Return enum of people, but throws an exception...
         NamingEnumeration people = ctx.list("ou=People");

Answer 1

I tried the same with a known LDAP service: OpenLDAP.org, and I get the same exception NameNotFoundException thrown with the following code:
     final static String m_ldapServerName = "OpenLDAP.org";
    public static void main(String[] args) {
     // Set up the environment for creating the initial context
     Hashtable<Object, Object> env = new Hashtable<Object, Object>();
     env.put(Context.INITIAL_CONTEXT_FACTORY, "com.sun.jndi.ldap.LdapCtxFactory");
     env.put(Context.PROVIDER_URL, "ldap://" + m_ldapServerName + ":389/");
     try {
         // Create initial context
         DirContext ctx = new InitialDirContext(env);
         // Return enum of people, but throws an exception...
         NamingEnumeration people = ctx.list("ou=People");