Thanks very much for the quick response.
I just tried both suggestions, which seemed to hold a lot of promise. Unfortunately, neither worked.
My detail bands are both based on the same view, we can call it dvStatementDetail. When dvStatementDetail.GroupType='ADJ' it's a payment/adjustment line and I suppress band A. When it's ='DETAIL' it's an invoice detail line and I suppress band B. Putting the conditional suppress formula from band A into band B's INVNO suppress makes it always suppress that field.
When I tried the other suggestion, having the suppress tied to Previous(dvStatementDetail.INVNO)=dvStatementDetail.INVNO, it didn't ever suppress the second INVNO.
I thought of something, though--I see each item on the report in XI R2 has an "Object Name" associated with it. Is there any way to refer to fields within a suppress formula based on that?
If it weren't for the ones where all the activity for the month is payment/adjustment activity I could just leave the second INVNO off.