You have started at least three differant threads on this issue. Instead of starting new threads, please keep it to one thrread, this will help us give you better support.
By keeping the entire conversation contained in one thread, we can keep better track of previous advice.
from previous threads, I've pointed you to the ecart tutorial for troubleshooting checkout failures. What are the results you are getting from that?
can you post the full response that is returned? Are you getting the full response? if not, make sure you are using the correct bindings.
Are are you testing using express checkout? If so, there are two sets of bindings to use: "PayPal Authorize Express Checkout" and "PayPal process Express Checkout"
If you testing using Direct Payments, you need to use the Paypal Direc t payment bindings.
