More info:
-I was in contact with the latest purchaser and he indicated that the discount was applied in the Powerstore interface, but it didn't carry over to Paypal where he paid the full price of the item.
-He made another purchase of a different item and the same thing occurred; no record in the admin panel, coupon didn't work when transferred to Paypal, no confirmation of sale aside from the Paypal notification.
Here's my store;
www.stuntmonkeypedals.com