That article was all born of some kind of misunderstanding, though; when it was on Slashdot none of the TCP gnomes who tried to reproduce it saw anything remotely similar.
yeah, they commented about that on the bottom of the page.
UPDATE: Since this post got Slashdotted, I've been getting a pretty fair amount of e-mail, suggesting that the behavior we observed here might be anything from T/TCP to HTTP/1.1 pipelining to delirium tremens. Well, I should point out that this phenomenon was something we observed in 1997, before HTTP/1.1 was in wide use; both the client and server were using vanilla HTTP/1.0. As it turned out, it was actually the NT stack that was causing this to happen-- it didn't matter what client or server software you used. It even happened with our home-grown network test tools.
It's entirely possible that Microsoft has changed the NT stack in recent iterations so that this doesn't happen anymore. But if you're trying to reproduce the behavior, use NT 4.0 machines for worst results.