Hello Meir,

Yes, the macro is designed to work on a single line of unselected text.
This is because in the rest of the situations we have the right-click -> Convert Selection > Comment/Uncomment functionality or you can pull these two buttons onto the toolbar.
Agin, the latter just does not work for a single un-highlighted line of code - hence the macro.

I must add, this creates some uncomfort for me - split, non-unified functionality .

Hope Yutaka is listening: I suggest a change to allow commenting code regardless of whether a line is highlighted/selected.