1. Write a couple of paragraphs 2. Insert vertical space between them, custom 3 cm. 3. Do something "undoable", such as typing in extra text 4. Click on the vertical space, change to 6cm 5. Try "undo". Notice that the vertical space doesn't revert to 3cm, instead the "undoable" stuff before that change gets undone.
Seems the change to vertical spacing wasn't registered with the "undo" mechanism.
