basically we define a round as the period of time between payouts so you won't see round stats change till we hit 120 confirms on this first block.
What happens if another block is found before the first one has 120 confirms? How are the payout shares calculated then?
in case the last post didnt answer this one directly, we know and track which shares belong to which block and payout them out accordingly. Its just our statistics that follow a somewhat non tradtional approach. The data is all there in the databases appropriately its just how you choose to interpret and display this data which can be left up to preference.