In the single_item.pdf (manual) it refers to the "Return URL Behavior" saying that if your set rw = 2 and also set the return variable the "buyer will be sent back to the Return URL using a POST method [where] all available transaction variables will also be posted." I'm using the rm=2 and the 'return URL' to post 'single pay' transaction variables to a specific page for each product. I was testing last night and it seemed to work just fine, then suddenly it stopped sending the 'txn_id'. I was using the same amount, item_name and user to test - should this make any difference? If so, why doesn't paypal provide a way to put an account into test mode? Has anyone ever experienced this dropping of the 'txn_id'? Rex P.S. No one and I mean no one I talked to at PayPal knew anything about the rm variable. I had to simulate mutiple tests just to find out answers to basic questions.