Schedule block preview moves under preceding block.

Steps:
1. Go to Page.
2. Edit Home / Tasteful Planet.
3. Add an empty RSS block above the "Main Story" Schedule block.
4. Remove the RSS block.
5. Add an empty RSS block above the "Main Story" Schedule block again.
6. Verify the layout of blocks.
Actual: Block borders and previews are shifted and overlap (attached).
Expected: Block borders and previews remain in sync.