Updating Status of books

I have just setup a new computer, and added all my books to the library. They are all now marked as NEW (unread) if I sync my reader, I lose the information on which books I have read. If I open each book individually in reader it changes the status to blank (already read). I have a lot of books, and everytime I have a problem and reload my books, it resets them to new. Is there a way to mark all books as read or to mass update the status. I don't want to have to open each book individually!.