enigma1 - 10:07 am on Jun 10, 2012 (gmt 0)
The paypal standard is not IPN. If you want to do instant payment notifications you need a separate module and it's not included in the vanilla osc but there are contributions for it. The stock version uses now the paypal express where a token is generated once the customer logs in to his account and then returns to your store.
Also each of the paypal modules has different configuration switches that change some parameters passed to paypal. As of the paypal control panel you don't need to do anything there for IPN, other than knowing your email address or pal-id. Because these parameters with IPN (whether to auto return to the store etc) can be controlled via the module's code.