I'm having troubles with this hack.
I'm using it in cover mode, which used to work fine (for like two years), but all of a sudden it stopped recognizing the covers and now it only ever shows the "The ScreenSavers Hack is currently in 'cover' mode, but hasn't yet successfully processed a book cover

" message.
I send all my books to the kindle through calibre, where I always add a cover in the metadata beforehand.
How can I troubleshoot this?