We're using Membership with BP and not sure about the "serial subscriptions"...
The idea is: one user remains X months in a level and then it is automatically renewed at the same level... So PayPal charges this subscription each X months, right?
Ok, but if the user cancels the payment in his/her PayPal account, what happens? Membership will not have any idea about this, no?
So the normal use of this plugin has to be: define a subscription for each X months, and then automatically downgrade the user, until he pais again, no?