gTalk connection error?

Hello again,

I got this error log when I tryed to login to gTalk server:

stream:error (text)
at org.jivesoftware.smack.PacketReader.parsePackets(
at org.jivesoftware.smack.PacketReader.access$000(
at org.jivesoftware.smack.PacketReader$
Sep 8, 2008 1:11:08 PM org.jivesoftware.spark.util.log.Log warning
WARNING: Exception in Login:
No response from the server.:
at org.jivesoftware.smack.NonSASLAuthentication.authenticate(NonSASLAuthentication .java:58)
at org.jivesoftware.smack.SASLAuthentication.authenticate( 232)
at org.jivesoftware.smack.XMPPConnection.login(
at org.jivesoftware.LoginDialog$LoginPanel.login(
at org.jivesoftware.LoginDialog$LoginPanel.access$400(
at org.jivesoftware.LoginDialog$LoginPanel$1.construct(
at org.jivesoftware.spark.util.SwingWorker$
at Source)

I have entered my username and password correctly, ‘’ as server name, and Spark gave me “Invalid username or password” error!

Does anybody know how to fix this problem???