Xperia Active :: Exercise Tracking Difficult Because Active Accelerometers Fail Intermittently?

I have an app, Activity Classifier, that uses the handset accelerometers to provide information on activities and total exercise. It automates exercise tracking, classifies activities by type and quantifies aerobic intensity. Live data streamed from an Xperia Arc using the app is displayed in a blog. While it is possible to use on the Active it is unfortunately more difficult on the Active than the Arc because the Active accelerometers have a fault that is hard to get around. The problem is that the accelerometers sometimes take quite a while to start sampling when either started or the sampling frequency is changed.Occasionally it can take longer than 90 seconds. The problem can be seen with the app Accelerometer Frequency. Switch between sampling frequencies and notice that sometimes it switches instantly and sometimes it doesn't. To minimise battery consumption Activity Classifier acquires data from the accelerometers for 6 seconds out of every 30. If no other app is using the accelerometers they will start and stop every sampling period. On the Active they frequently don't start and the app detects a faulty accelerometer. The app has an option to keep accelerometers on and if this is selected it will work OK but battery consumption goes up a lot. The Active comes with a pedometer app called Walkmate. I can see from the Accelerometer Frequency app that Walkmate keeps the acclerometers running at 50 Hz and running Walkmate at the same time as Activity Classifier will make Activity Classifier work OK as well. Walkmate seems pretty power efficient and uses less than half the power of the market leading pedometer app Accupedo, run in power balanced mode, but it counts a different number of steps.