Paypal just emailed me that a payment to me from 1st June "didn't go through", and in my account the payment says "cancelled". This has never happened before, that a month after receiving the payment (which was never listed as pending or anything like that), it gets "cancelled". I don't post items until the payment has gone through - obviously I posted this four weeks ago.

eBay doesn't show the payment was cancelled or anything unusual (the buyer never reported the item was not received).

Does anyone know how this can happen?