This is the second time this happened. 
Yesterday, I used my itouch to do writing reviews and my iPad mini to do tones/definitions. Today when I synced both devices multiple times , the writing items didn't go to the iPad mini, and there is a difference of about 300 writing  items between the two devices. 
Also, I remember reaching 2 hours of study last on my itouch , but the site's progress tracker says I only did about 90 minutes .
    


