Having this issue today. Got an order and it is in zencart admin but not in paypal. I called paypal and it is a problem and they know about it. I did advise them that the time stamp of the paypal transaction (Timestamp: 2016-03-17T16:48:33Z) ,6 hours in the future(if it is all pacific time)! That could be why it does not show in paypal. The time-stamp in zencart (03/17/2016 10:48:34) was correct. I am also getting this message"There was a problem retrieving transaction details. (Transaction refused because of an invalid argument. See additional error messages for details.) 10004" on top of the admin page under "processing". Does zencart hit paypal to get info, every time I load this screen?