MSN Messenger connectivity problem

Windows XP Pro SP2 & MSN Messenger 7.5. Sometimes have great difficulty in
signing in. I use the "Troubleshooter" and this shows that Basic Internet
Connectivity Test are all ok. Still will not allow me to sign in.
2nd Problem: I usually make a connection early in the evening but around
20.30 - 21.00 the connection is lost! This happens just about the same time
every night. And when trying to reconnect I get problem Number 1. Rebooting
the computer does not help. Using "Troubleshooter" gets the same results as
above :-(
HELP needed please.


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