I guess I need to report this for it to get fixed.
At first I thought this happened with any lines, but actually it seems to specifically affect using lines.
Pretty easy to replicate:
- Select at least 2 full using lines. (The lines at the top of most source files.)
- Use Ctrl-Alt-Shift-DownArrow to move the text down within the using list (make sure you have enough usings).
- After one move, the last line is no longer selected as a line, but still selected enough to keep moving.
- Use Ctrl-Alt-Shift-DownArrow to move the text down again. (Can also move up.)
- Now the last line has lost 1 character of selection and no longer counts as being fully selected.
- You can no longer use Ctrl-Alt-Shift-Arrow to move the text because you no longer have full lines selected.