Ok, this is interesting. After looking at the oddity in Kaos' screenshot where the lag dropped his framerate down to 3, I've been going around trying to reproduce it on different servers. I had a small spike on the "Raritan high School!" server where it happened. It actually caused the game to stutter and gave me a brief dip in framerate. Then I went to some foreign server with a 250 ping, consistently higher than the small lag spike I had, and it had no impact on my framerate. It's not just generic lag. Something is causing the sockets to block, I think. But what? The sockets are set to be non-blocking. Somewhere along the line, though, there's a hold-up while receiving data from the server.