Problem: First name and last name do not go through to Authorize.net.
 
Solution:
 
If you are using Authorize.net, be sure to use separate First and Last name fields on the order form so that the data passes into the Authorize.net (AIM) system.
 
Go to: Admin - Orders - Order Profile Page Settings - Predefined Fields.
 
Un-check the single "Name" field and instead check the "First Name" and "Last Name" fields for both Personal and Delivery (if desired).
 
This will enable the first and last names to be passed through the Authorize.net AIM payment system.
 
The default when I installed (Dec 2008) the trial version was to have the "Name" field checked and the "First Name" and "Last Name" fields un-checked.