I'm seeing exactly the same: big latency and a lot of timeouts. When posting a tweet, Twitter sometimes does not return a response within 30 seconds. After my curl times out, the app has no way of knowing if the post made it or not. Sometimes it will appear on Twitter and sometimes it won't. This effectively breaks our app. Replicated the error on two different servers (in the Netherlands) and with different accounts.
I would very much appreciate a reaction from Twitter on this. We are in the process of switching to OAuth, but I would like to know if I have to implement a workaround while we're on the old system. Thanks, @tjaap