OK, we're using Website Payment Pro with e-j, and did two test transactions using an employee's credit card (not a PayPal log in) here at the office.
Both tests worked perfectly. The customer's card cleared right away, and the confirmation page came up with no delay.
We (the sellers) received notification of the transaction from PayPal right away.
However, the buyer received no email, from the us or from PayPal. We checked spam folders, and did a re-send of the email from the admin page. Nada.
I've been through the forums thoroughly and can't seem to skin this cat.