In response to the overwhelming amount of Guest that have decided to post replies to topics that are extremely old, I have had to disable their ability to reply to topics.

So for now on, guest users (non-members) are not able to reply to any thread/post.

These guest have 2 solutions:

1) Sign up as a member (free) & reply to the thread.
2) Create a new thread.

I have decided to allow guest to create new threads as this has not really been a problem yet. However I will be monitoring this closer now with the new non-guest post configuration set in place.

I encourage guest to sign up (for free) and then pitch in their words of wisdom.