getRoster never returns a roster

Hi all

Am I missing something ?

connectionConfig.setRosterLoadedAtLogin(false);

conn = new XMPPConnection(connectionConfig);

try {
conn.connect();
} catch (XMPPException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
conn.login(USERNAME, PASSWORD);
} catch (XMPPException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
roster = conn.getRoster();

getRoster seems to do nothing.

If I set setRosterLoadedAtLogin(false), I should be able to get a roster later on ?