I just tested this out running a remote script using Net::Telnet (which I assume you are using as well). I couldn't replicate your error, sadly.

One thing to check might be the record separator parameters for the cmd function. If changing them from the defaults doesn't work, I believe you can also send a scalar reference that it'll dump all the output into. You could then break it up yourself, at least.

Edit: beaten. I have to learn to start refreshing the page before I submit a node.