Problem in calculating Sub-Totals

Hi

Currently i am designing a report, where in client requires to display the subtotal, where i am facing a problem.

Scenario

Say there is a Agency A, In Region R.

Each Agency has multiple clients.

Need to display the totals based on Agency.

first level break is on Region and then on Agency.

I use sum(TransactionRevenue) to calculate the total for Agency A.

Rather than calculating subtotal for A, it calculated the total for entire report

Can anyone help to resolve the problem