We'd been having some trouble with the transmitter eating batteries like candy for a few weeks, and then the receiver suddenly being super slow to respond when buttons were pushed. It finally just up and died. We used it intermittently for 6 months and continuously for 7 months. This is the ONLY issue we've ever had with it. No sensor errors, nothing! But now that our study is over we can't get a replacement. They did send in a request to our insurance company, so we'll see. We have an appointment tomorrow to test the Dexcom 7 for 3 weeks. I REALLY miss that Navigator! I definitely don't sleep as well at night now. It was so incredibly accurate for us. Here's hoping our insurance will pick it up!!