It sounds like the IPN messages from PayPal are not being sent from PayPal or are not being accepted by the extension.
First, you need to check and see if the IPN messages were sent from PayPal.
1. Log into your PayPal account
2. Go to History>>IPN History
3a. You should see a list of recent IPN messages, they should include you recent subscribers
3b. Were there any IPN messages? Were the IPN messages sent out successfully? If so, then you have set up your PayPal profile correctly to handle sending IPN messages to your site. If not, then you need to double check your PayPal profile's settings to ensure that IPN is enabled. Please refer to the extension's documentation for details on how to do this http://trinitronic.com/index.php/Joomla ... alsettings
Now that you have determined that PayPal is set up correctly, you need to find out why those IPN messages are being ignored.
1. Log into your Joomla site's admin area.
2. Go to Components>>Nice Memberships>>Settings
3. Tick the check box to enable the "IPN Log" you will find it at the bottom of the page.
4. Click the save button.
5. Log into your PayPal account and go to History>>IPN History
6. Click resend on one of the subscription IPN messages.
7. It will take PayPal sometime to resend the message. Be patient. Once the message has been resent, go back to your site and navigate to Components>>Nice Memberships>>IPN Log.
8. Click into the IPN message in to log. What does it say? Usually this will give you some clues as to why the extension is not allowing the IPN message to pass through security.
Remember to turn off the extension's IPN Log when you are finished testing. It is not appropriate to leave it on for a production site and could cause unforeseen issues to arise.
~ Best regards