Bear with me if this question has already been asked, as I am new to this forum =) My son just started using the Seven Plus a couple of weeks ago and we have so many issues with false highs and lows. When I calibrate it with his fingerstick reading it continually says error because the readings are obviously not matching up. I called the company and they did send out a replacement, but now my son doesn't really want to use it anymore because it is frustrating with all the false numbers. Any suggestions so the new one doesn't do the same thing? Thanks!