I fixed mine – it’s been months since i’ve had time to look at it.
I changed my paypal.php file slightly (only a few lines) and you can download the new version at:
http://www.umpcportal.com/wp-content/plugins/donate-plus/paypal.php.txt
Basically I took out a trim of the returned result (trim is not used in papyal code examples) and switched to SSL.
I also enabled IPN tracking at Paypal in accordance with the instructions…
http://www.umpcportal.com/wp-content/plugins/donate-plus/paypal.php
This is your IPN Notification URL. If you have issues with your site receiving your PayPal payments, be sure to manually set this URL in your PayPal Profile IPN settings. You can also view your IPN History on PayPal
…but I don’t think this makes any difference as it’s for a different type of process.
Hope it helps.
Steve.