Here's how SAP works. You cannot charge to 2 "Real" Cost objects at the same time. One of them has to be statistical. So if you are making a posting to a Cost Center and a WBS (both are cost objects) at the same time one is statistical. On the WBS there is a statistical checkbox.
The posting to the statistical object has a different value type. In reporting that's how you know which is which.
CJI3 only shows PS object postings (a cost center is not a PS object)