My computer was keep disconnecting from network, I think it happens when I am doing high network usage. After I remove the network cable and reconnect, it works for while.
System Event log has few of these,
Log Name: System
Date: 4/19/2011 6:23:00 PM
Event ID: 1014
Task Category: None
User: NETWORK SERVICE
Name resolution for the name yp.shoutcast.com timed out after none of the configured DNS servers responded.
I found this FORUM POST with few solutions. The one worked for me is to disable Receive Side Scaling in network card advanced properties. I hope this helps if anyone suffers from this nagging issue.