I am working on a spreadsheet which has a large amount of data. I used the
data/subtotal function to show at each change in id. It looks great when
you're viewing all data at level 3, but when you go to level 2 to see the
summary subtotals, they show as 0... why is this happening? This is the
whole reason for entering the subtotals.

invoice id amount
001 123 84.84
001 123 22.18
001 124 16.15
001 124 6.37
002 125 37.05
002 125 42.05

I am also having trouble adding a second layer of subtotals. I would like
to also subtotal at each change in invoice number and it isn't working out.