VOIP jingleManager is always null

the following code never return (step with the debugger) from mediaManagers.add(new SpeexMediaManager(transportManager)); this is taken this code out of spark therefore my jingleManager is always null any idea

final SwingWorker jingleLoadingThread = new SwingWorker() {

public Object construct() {

String stunServer = “stun.xten.net”;

int stunPort = 3478;

if (STUN.serviceAvailable(SparkManager.getConnection())) {

STUN stun = STUN.getSTUNServer(SparkManager.getConnection());

if (stun != null) {

List<STUN.StunServerAddress> servers = stun.getServers();

if (servers.size() > 0) {

stunServer = servers.get(0).getServer();

stunPort = Integer.parseInt(servers.get(0).getPort());

}

}

}

JingleTransportManager transportManager = new ICETransportManager(SparkManager.getConnection(), stunServer, stunPort);

List<JingleMediaManager> mediaManagers = new ArrayList<JingleMediaManager>();

// if running on Windows use Direct Sound for better performance

String locator = Spark.isWindows() ? “dsound://” : “javasound://”;

mediaManagers.add(new JmfMediaManager(locator, transportManager));

mediaManagers.add(new SpeexMediaManager(transportManager));

jingleManager = new JingleManager(SparkManager.getConnection(), mediaManagers);

if (transportManager instanceof BridgedTransportManager) {

jingleManager.addCreationListener((BridgedTransportManager)transportManager);

}

else if (transportManager instanceof ICETransportManager) {

jingleManager.addCreationListener((ICETransportManager)transportManager);

}

return true;

}