[AccessD] Curious behavior with Hide Duplicates and groups

Using the Hide Duplicates property with the one value is Okay -- if you use it with a many value, you're liable to hide a duplicate value when you don't want to. For instance, in the case of items in an order. You can easily hide the duplicate order id values without worry. If you hide product names for the items in each order, you can run into trouble if the first item in a new order is the same as the last order in the preceding order. The Hide Duplicates property doesn't respect grouping. 

What I saw today is that it does -- if you force it. 

Adding a group isn't enough -- if you group on the order id, the Hide Duplicates property still evaluates the entire report as one group. If you display a group header, bingo... Hide Duplicates respects the groups. 

Okay, so this is cool, but why do you have to display a group header to get it? 

Susan H.