Reqs User Agent
5,378 Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_2) AppleWebKit/536.26.14 (KHTML, like Gecko) Version/6.0.1 Safari/536.26.14
We were able to track it down to a retry mechanism for streaming content when the server was responding too slowly. Maybe you are running into something similar.
So the problem's already been fixed as far as they can tell.