We've been using the same transmitter for just over 3 years, and suddenly it's behaving strangely. It's doing things like changing the amount of time needed between calibrations (e.g., going only 6 hours, not 12 hours), and putting itself into warm-up mode as if we'd started a new sensor but we didn't. These are not what it does when it's at the end of its battery life or the sensor itself is going bad. Has anyone else seen things like this when the transmitter was at the end of its useful life? Or is this likely something else? I know I should probably just call MM about it but, since it's not a critical issue, figured I'd check here first to see what other people's experiences have been. Thanks!