Hi, sorry I didn't get back to you earlier. I was only monitoring this thread: http://code.google.com/p/twitter-api/issues/detail?id=1543
Right now about 10% of our post fails immediately. Latency is between 0.7s and 3s, with peaks to 7 or 8 seconds. We are not logging tcp dumps at the moment, but I will see what I can do. I also will try to get some more data from our logs to see when this is happening the most. Thanks Ryan and John for looking into it!