There was a modification to contactID being added to AT tickets with the 22.214.171.124 build released Jan 8th 2014.
The Synchronizing Tickets doc has been updated:http://docs.labtechsoftware.com/documen ... n%7C_____6
Now has new NOTE section as follows:
NOTE: The Autotask® Contact ID is added to a ticket when it is sent to Autotask®, if the email address associated with a ticket matches a specific contact in LabTech and that contact is also mapped to an Autotask® contact. If that method fails, contacts are added to tickets if the following conditions are met: ticket has a computer ID, computer has a contact associated with it and the contact is mapped to an Autotask® contact. If neither of these methods are successful, an Autotask® Contact ID will not be added to the ticket.