If your users are getting to the checkout failure page this usually only happens if there is an error during the transaction processing. What page are your users getting to when there is a problem? Have you been able to apply the full request and full response bindings to the page to see what result you are getting?
If you cannot get a meaningful result with these values and you would like someone to take a look at your files just let me know and I can open a ticket for you that will let you post the files privately.
Thanks for the insight. I am still testing on my end. The last three attempts went through okay. I am going to try another test this afternoon. If the problem persists, I will gladly accept the offer of the ticket and help. Thanks alot.