My servers are behind a firewall that has the annoying habit of disconnecting teh ssh clients on inactivity.

I can solve this on my local Unix shells by using the ServerAliveInterval in /etc/ssh/ssh_config and that keeps the connection open fine.

However, I can't find the equiv of this in the PhpEd ssh terminal and hence these still drop. Is there a way to send the inactivity probe packets from the PhpEd SSH Terminals?

These idle packets are expected to be sent by your server and they are supported by PhpED's ssh terminals too. Please make sure that the period is short enough, for example 2m.

If you still get the problems, please stop sshd daemon, run it from a root console with -D -ddd options and redirecting the output to the log file:
/usr/sbin/sshd -D -ddd >/tmp/logfile 2>&1

Please note, that in this mode you'll be able to run just one ssh session and sshd will quit after it.

After you get the problem replicated, grabthe log and send it to me or make it available online for me.