WBS Orig. Budget Vs. WBS Activities Roll-up Sum. Budget

I currently have a schedule that is resource loaded. I have entered the ‘Original Budget’ into to each and every WBS (which mimics the pay items on the contractor’s submitted invoice). I have also resource loaded each and every activity (budgeted units/cost etc ;).
I am wondering how this are related from a cost point of view. I thought the budgeted cost for each WBS should equal the summary roll-up cost for activities under that specific WBS. This does not appear to be the case (maybe I am not showing the correct Columns?)
Example
1.0 WBS $500,000
1.01 Act 1 250,000
1.02 Act 2 100,000
1.03 Act 3 650,000

Any assistance is much appreciated.

Thanks