This is more likely an issue with Parallel::UserAgent, but I couldn't resist that title ;)
I'm using POE::Component::Client::UserAgent to fetch multiple RSS feeds. Every once in a while, one of the servers is down, so that request times out with a 500 error. The problem I have is that all requests that are queued behind this one also time out with a 408 error!
I don't feel like starting a bug hunt on monday morning; and this one looks like it's going to be hard :(