1. Apply a style to some text.
2. Make some change to this paragraph which changes the layout of the paragraph in some way. For example apply a first line indent different from the one in the original definition.
3. Now remove the override (I always do this from the paragraph styles panel).
4. The override is indeed removed, but the paragraph doesn't redraw, and it's unreadable until I page up/ page down, which forces the redraw. This certainly isn't the end of the world, but it would all run a lot faster if this didn't happen. :)