I'm getting the "Unable to verify POST vars"... have done all the troubleshooting I can based on other tickets.
If i generate the button from paypal it works fine, but when using the plugin I get the error, all settings are quadruple checked.
I downloaded these files curl-test-http-google.php
curl-test-https-paypal.php
fopen-test-https-paypal.php
and all three brought up blank white pages. Does this contradict the fact that everything works fine when using a paypal generated button?