PemBer 1.5.2 fixes two bugs discovered since the release of PemBer 1.5.1. These bugs were related to the introduction of multiple Paypal in PemBer 1.5.1. 1> User could get a session expired error due to Live paypal signup going to Sandbox. 2> "Request Not validated" in transaction log because Paypal sandbox mode is wrongly detected. This also resulted in "Refunded" transaction not downgrading the user. If you are on PemBer 1.5.1 it is recommended that you upgrade to PemBer 1.5.2 from the PemBer Releases forum to fix the issues.