I have customized my status bar to I can see the selected Number of Characters and the Number of Lines.
If I select any number of lines by clicking and/or dragging in the left column it shows the correct number of characters and lines. However, if I then shift-click some line further down on the page to enlarge the selection, the number of characters and lines in the status do not change.
Edit: This also applies for any existing selection being expanded with shift-click.
Edit 2: On a similar but different note, if I create multiple selections, the status bar shows the char/line count of selection added last. (not sure this is a bug or by design)