Kindle Hacks
1) Set the Synchronization off on the amazon
Go to Amazon -> Your Account -> Manage You Kindle -> Manage Kindle Device Synchronization -> click the “Turn the Synchronization off” button to turn off the synchronization
2) Exit & re-enter your book. Go to the begging of your book on your kindle and try to sync the furtherest position. It should say that you’re currently on your furthest location.
3) Turn on the synchornization setting on the Amazon
4) Exit & re-enter your book.
NOTE: This is no longer necessary. In your “Your Account”, there is a Manage Digital Content section. Find the Kindle area and locate the book you want to reset. On the far right there is a drop down and one of the options is to reset the furtherest page read. Thank you Amazon! Now please give us that functionality in the damn Kindle apps!