Hi Gary,
I've run a couple of test responses. It seems that the thread has automatically unsubscribed us to the email updates. On the right side of the screen you'll see a box titled thread options. In it is an option called "email subscribe to replies to this forum". Click that and you should be good to go.
I'll start a ticket with our tech boys and see if they can fix the thread. Probably a misplaced 1 or 0.
Thanks!
Tim