I bought my tracker less than a month ago and it was working pretty well until two days ago...the latest update made my tracker not monitor my sleep. For two days now my tracker does not track and or update my sleep. This was the main reason for the purchase of the tracker, now its pretty much worthless. I know it sounds far fetched that the main reason for purchase was not for walking/run tracking but for sleep monitoring. Well I have problems with sleep and wake up a lot at night and was happy to find a way to track it. Oh well now. Worthless. Please go back to previous version.