So it looks like there is a big battle of digital rights between authors and publishers in the States.
See here for the Guardian article: http://www.guardian.co.uk/books/2009/dec/15/stephen-covey-amazon-ebook-deal
Random House in New York is asserting their rights to digital versions of their backlist titles, to the displeasure of authors and their agencies.
In the UK, however, there is an 'understanding' between authors and publishers that the digital rights belong to the author, though the author would not abuse his/her ownership by selling it to a third publisher.
Digital publishing is such a complex issue, due to its intangible essence, and new rulings are constantly sought to establish fair laws to govern this young area of property ownership.