Steps to regenerate
The data is missing both form Strongly Typed event argument object and PostedData["..."].
This problem is not there in IPN_Notified event.
The BuyNow button's last line data is 'charset' and so, e.Charset is not available from PDT data.
For Upload Complete Cart Button, payment_gross is the last line data in the PDT raw string and so, e.PaymentInfo.PaymentGross is never received.