Today at my computer CGMiner can't connect to any pool other than a local server, but I am having no problem with phoenix so it is not a networking problem. Is there anyone having the same problem?
Changing URL (btcguild.com:8332) to a fixed IP in their cluster fixed the problem. It seems they have a cluster now - each time I ping the server btcguild.com it would give a different ip address in network 78.46/16
Perhaps CGMiner stored the IP address resolved at the first place, expecting response from this IP address, but performed a reconnection and got a different IP address before retrieving initial work, therefore get confused? Just my guess.