Indication of self-translation

Rarely one finds a discussion in the press about the habit in the publishing industry to present self-translated books as originals with no reference to the other version. So I found it quite interesting that in her review of the new book by Thiong'o in the Guardian, Maya Jaggi recently drew the readers' attention to the fact that Dreams in a Time of War is in fact a self-translation from the Gikuyu although it is not mentioned in the book. She finds this quite disturbing as in the past Thiong'o "has said that the most beautiful line in Wizard of the Crow, his satire on dictatorship, is: "A translation from Gikuyu by the author." (Jaggi 2010). So what has changed since then?

For further reading:
Maya Jaggi (2010): Dreams in a Time of War by Ngugi wa Thiong'o. In: Guardian, 03.07.2010. Online available here. In the last paragraph she discusses the issue of self-translation.