When a subscriber is manually added, Under Subscriptions, ALL of the dates change to the date the most recent subscriber was added for all subscribers. ie If I added you as a subscriber 10 days ago, and today I add Mary, the Created Date for you will depict todays date. It should be the date you subscribed, which would have been 10 days ago, in this example.
This date change may also be true when someone subscribes with the widget. keep an eye out for that. What other possibilities are there? Consider those too.