tmride--It sounds like you're going to have to reformat your reader...sorry. But if you haven't deleted the books from your computer, you should be able to transfer them over again from your computer once the 700 is re-formatted.
Also, if you have deleted the books from your computer, try plugging your 700 into your computer to see if the computer will see your 700 as an external drive. If it does, you may be able to copy the books off of it and on to your computer before reformatting the 700.
Good luck!
dordale