Empty transaction amount

Using data preload, on US production site, Moneris Payment Details page show transaction amount as empty - Transaction Amount: $ (USD). Works fine on the development site for the same configuration with the exception of development URL.

More details:

• URL - https://www3.moneris.com/HPPDP/index.php
• Amount sent is in decimal (e.g. 1750.00)
• Values sent - hpp_id, hpp_preload, ticket
• PHP

What am I doing wrong?