The module does not work with Ubercart 1.6. It works perfect in a test environment using the "Test Developer" mode, but there are errors every time it runs in production against a live Authorize.net connection. The error messages in watchdog are as follows:

Type: php
Location: /cart/checkout/review
Referrer: /cart/checkout/review
Message: unserialize() expects parameter 1 to be string, array given in /sites/all/modules/ubercart/uc_cim/uc_cim.module on line 380.
Severity: error

Type: CIM
Location: /cart/checkout/review
Referrer: /cart/checkout/review
Message: Customer payment profile could not be created. User: 15, Error: The transaction was unsuccessful.
Severity: warning

Type: uc_cim
Location: /cart/checkout/review
Referrer: /cart/checkout/review
Message: CIM Charge failure. Raw gateway response: . Raw CIM response: The transaction was unsuccessful.
Severity: notice

Type: uc_payment
Location: /cart/checkout/review
Referrer: /cart/checkout/review
Message: Payment failed: Credit card payment failed: The transaction was unsuccessful.
Severity: warning