Text Orientation Switched in Compile

Something very strange has shown up in my compiled documents. Although the beginning chapters display correctly – i.e. left to right text, double spaced, first line of paragraph indented – the remainder of the document is one single line running down the left hand side of the page. The letters are in order but, obviously, there are only a few words on the page.
Does anyone know what has caused this and how to remedy it?

This a known bug and will hopefully be fixed in the next release.