Reordering a page (via Space Tools -> Reorder Pages) that has Task List macros that include dates causes duplicate tasks to appear under "My Tasks" view

Workarounds can be found in this KB article

Steps to reproduce

1. Create a new page in a space that already has some pages in it.
2. Add a task list macro, mention your own user account, add a date to the task (with '//').
3. Go to My Tasks, notice the newly-added task is only shown once.
4. Go into Space Tools > Re-order Pages, move the page with the task macro on it to above or below where it is now.
5. Go back to My Tasks, and the task on that page is now shown twice.

The task will be duplicated each time the page is moved.