I installed the plugins, add-ons correctly. Also added the filter functions to my functions.php page (just like it was explained here: http://rocketgeek.com/plugins/wp-members/add-on-modules/wp-members-subscription-module-with-paypal-integration/).
However when payments goes through successfully, it does not activate the user for the subscription period ?? I have to do this manually, via edit user > Extend user subscription.
Any help ??