I have used calibre very sucessafully so far with the reader. However at present I am having problems with a couple of books I have converted to epub. I have version 0.6.45. They read ok until the mid section and then the reader starts itself up again and goes back to menu and the reader does not even remember that it is the last book. Would anyone know what the problem is? it is a sony reader 505. Not sure if it is format or reader and it has happened on a couple of books. Any advice appreciated