Selection not extending correctly

2.0.3 / Win 7

Open the attached score.

1. Select the first measure, staff 1, by clicking on an empty space in the measure. Now extend the selection downwards using the Shift + down arrow. Result: The selection stops at Staff 2 and will not extend to Staff 3:

2. Deselect, then select measure 3, Staff 1, by clicking on an empty space in the measure. Now extend the selection downwards again using Shift + Down arrow. Result: Notice that when the selection extends to measure 2, the range decreases. And now the selection won't extend to Staff 3.