Gap at bottom when Row height is not uniform

Sep 25, 2008 at 2:25 AM
I'm using a DataTrigger in ElementStyle, to make some rows use different (smaller) font size when they match certain data criteria. The grid ended showing a gray gap at the bottom (This gap is definitely part of the datagrid, as I checked the visual tree using Snoop). The height of this gap is exactly the difference between normal row and smaller-font rows multiplied the number of smaller-font rows.
It's as if the the grid calculated the area needed to show its rows by calculating standard row height x number of rows.
How can I fix this?