Hi there,
Kathryn and I discussed this further, and we are still pursing an "official" answer; in the meantime, here is another option for you instead of using the captions:
Applying a margin to the image itself.
*Click on the image to edit it
*Click on Advanced tab
*In the Styles field, add
margin-bottom: 10px;
That will give you just enough padding on the bottom to pull your images up off of the line.
Hope that helps!