Just an update, we have just patched our forums to address the following issues:
1. Issues with unable to unsubscribe from a particular thread
2. Generating e-mail notifications when a reply is edited.
Having said that, while we were working on these issues, we also realized that if you have initially posted a question, you are not automatically subscribed to the thread (This was a bug in EasyDiscuss 3.x) and when we reply to the thread, you might not receive these e-mail notifications.
For newer posts, you will automatically be subscribed to the thread when you post a new discussion or reply. Clicking the unsubscribe would unsubscribe you from the thread.