The problem has been determined to be your Authorize.net account info. When using our own account details, it works fine. A screenshot was emailed to you to show this. Thanks.
This transaction failed due to an error in application. Please notify the site administrator and provide the text that is displayed below:
Reason :(TESTMODE) This transaction cannot be accepted.
Verified Auth.net id/key
Tried it in testmode and live. Still does not submit to authorize.net:angry: