[O] text colours after upgrade

[Paul Rudin]

Having upgraded org-mode via the emacs package thingy today I notice
that sometimes the text following a heading is coloured as the heading.

This seems to depend on some internal state, as the same file contents
does not always result in this happening. So, for example, if I save the
file and re-open it the text is coloured correctly.

I've yet to identify exactly what needs to be done in order for this to
come about, but I have noticed it a few times this morning...