With no changes on our side and perhaps related to POODLE/SSL3 our PayPal API call to PPIPNMessage::validate is now failing with.
SSL routines:SSL3_READ_BYTE
Use this setting in your paypal class on calling function PPHttpPost()
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false); curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false); curl_setopt($ch, CURLOPT_SSLVERSION, 6); //6 is for TLSV1.2