RTMPT clients disconnect sporadically

[edgul]

I'm operating a text-based streaming newsfeed. I'm dealing with a client behind
a proxy server. The client is connecting on an rtmpt connection on port 80. The
initial connection works fine and the client receives news. The connection
stays open for a while -- typically for 2 - 5 minutes, but occassionally during
off-hours up to 45 minutes. Then the FMS server reports that the connection has
closed.

Obviously, something is going wrong with the connections through the proxy
server. The fact that it works better off-hours makes me think it has something
to do with the overall demand on the proxy server.

A few questions...

The client isn't explicitly closing the connection. So how exactly does the
server decide that a client has disconnected?

Is there any way to configure the client or server to tolerate the proxy
dropping the occassional message?

When talking to my clients proxy server admins, what could they adjust to help
the problem?

[CaptainMOB]

I am having the same issue although it works fine when I connect using an IP instead of a host name.