We recently found a bug with the page turner. If a user selects a folio by using the text box and then goes to the next page using the slider button or corner/edge dragging, the book will flip forward one page and then immediately back one page.
The source of the problem appears to be the flash application, but its not entirely clear. For the time being we have removed the slider and disabled corner/edge dragging. Pages can still be turned by clicking on the larger buttons pointing right and left.
Alternatively we could keep the slider and dragging behaviour by having the text box reload the entire page turner when a folio is entered. Let us know if you would prefer this option.