As a followup to my earlier note... Please note that I disabled the following option in all member's Profile pages... "Turn notification on when you post or reply to a topic."
This option was never set to be on as default but it appears that some members may have changed it at some point and then forgot how to turn it off.
If you wish to be notified of replies to your posts please take the time to go to your Profile tab, click the Notifications link on the left side of your screen and then enable the said option. Don't forget to click Save Settings.
Apologies for all the inconveniences caused. Hopefully this will address the issue.