In the attached image collage, the vertical line is meant to divide the left column from the right column of a two-column layout.
Extending the line to the bottom of the Detail 1 band causes the row below the line to print, even when that row has "Remove Line When Blank" selected. (Denoted by the red X.)
If the line is not extended, then gaps are shown in the line for the last row of the subreport (the one that lists dependents).
It would be great if there was a way to remove an element in a report based on the "blankness" of a different element.