When zoomed in on an image, creating points with the Multi-Point tool places the points with the correct x but shifted in y towards a slope=-1 midline.
e.g. zooming in the top-left corner, all points are placed accurately:
zooming in an upper-right section, points are placed below the cursor:
zooming in a lower-left section, points are placed above the cursor:
@Wayne does this happen in the latest ImageJ?