Events in Shopping cart approval process

Hi All- I need to know when the events Changed and ChangedAndAcknoledge for BO- BUS2121 (SC) will get triggered. We are using ACF WF.

My Problem is, when the approver changing Quantity or Price, before approving, then event- 'ChangedAndAcknoledge' is getting triggered. But if approver changes any other apart from Quantity or Price (say- cost center), then event 'Changed' is getting triggered

So do we configure any where, how this events to be triggered? Please provide your inputs

PS: I am using badi- BBP_WFL_SECUR_BADI and setting security level as '2'

Regards

Vinoth