Hi Ben,
I’m sorry about the delay in getting back to you.
I’m gratified to hear that secondlife.com are using this, I’m a big
MMO fan myself 
I’d appreciate any comments you have on improving usability of the
clients (they’re not as slick as they could be).
Which web server are you using for your Rails FastCGI setups? I’m
aware of intermittent issues when using Apache 2.0 and FastCGI, which
people have worked around by using LightHTTPD instead.
It sounds like a stability problem at the handler end, as under normal
operation the server should not arbitrarily close the connection (the
cause, I suspect, of the EPIPE error).
Regards,
Leon