I want to add another +1 to suffering this problem. I have had the SensorTag lock up fairly frequently (5-6 times today) while using both the SensorTag iOS app and my own app.
This lock up can occur while sensor data is being read. The SensorTag will suddenly disconnect with all LEDs off. Pressing the side button has no effect, no LEDs will come on, until the battery is removed and replaced.
Holding the side button for 5 seconds has had no effect whenever I've tried it. Neither has switching Bluetooth off/on on the iOS device.
I have been testing with an iPhone 5 running iOS 6.0.
If there's any more information or any specific testing I can do to help track down this issue, just shout.
Cheers, Chris
