If you can't see your sale on MyDD transactions, then please check the following :

1. You didnt set your IPN url correctly in your paypal account
(Your paypal account should be premier or business)

To fix this, log into your MyDD admin area and from the
right menu, click:
"I received a payment but nothing happened"

Follow the instructions

2. Your Primary Paypal email does not match the one in MyDD
under Edit->Preferences

Double check to make sure which is your primary email in your
paypal account.