My asp site paypal gateway needs some modification

I have a asp.net website specialized in fine arts picture purchasing/downloading for clients. The paypal gateway used to work fine, meaning...money can transfer, plus the buyer can get the download link of the the artwork. However, when I changed the paypal from one payee(one who receives payment) to another payee...the paypal transaction is stuck. What happens is that the payment can still go through, but the buyer didn't get confirmation email nor receive the order ( a email with download link). My observation is that the session id is NULL for this type of transaction. I can't think of the difference between two payee paypal accounts. THe only difference i could think of is the previous paypal account is a personal account, whereas the latter not-functioning paypal account is a premier account. Another difference is that the former account is from Australia, whereas the latter is from America. But I doubt this is the problem. Can somebody help me resolve this bug? I will provide you the asp code to look at. ## Deliverables 1) Complete and fully-functional working program(s) in executable form as well as complete source code of all work done. 2) Deliverables must be in ready-to-run condition, as follows (depending on the nature of the deliverables): a) For web sites or other server-side deliverables intended to only ever exist in one place in the Buyer's environment--Deliverables must be installed by the Seller in ready-to-run condition in the Buyer's environment. b) For all others including desktop software or software the buyer intends to distribute: A software installation package that will install the software in ready-to-run condition on the platform(s) specified in this bid request. 3) All deliverables will be considered "work made for hire" under U.S. Copyright law. Buyer will receive exclusive and complete copyrights to all work purchased. (No GPL, GNU, 3rd party components, etc. unless all copyright ramifications are explained AND AGREED TO by the buyer on the site per the coder's Seller Legal Agreement). ## Platform All platform