How to populate the resource cost rate in the project budget (2012)

Question:
A resource is assigned to a task with a Planned Start date of 01/Jan/2013, and a Planned End date of 01/Aug/2013. The resource has a cost rate with an effective date of 01/Apr/2013. The cost rate for this resource is not populated in the project budget. Why is the resource cost rate zero in the project budget, and how can it be populated in the budget?

Answer:
Resource rate is calculated based on the task assignment start date. Since the only active resource rate is effective from Apr 1st, the cost rate for this assignment will be zero.

Add a new rate with an effective date prior to Jan 1st in order to have a non-zero cost rate for this assignment.