Did you start messwerk to see if it was still showing something for accelerometer or orientation? Maybe it was the effect I described before where lipstick lost orientation sensor capability.

Anyhow I advise everyone to stop using watchdog and just replace the sensors so file like described in my post.
It works way better this way and running it for a couple of days I can clearly see an improved battery life.
The memory leak thing is a minor issue in my opinion as it is not always doing it. I have a memory usage about 3 MB for 2 days already so its not even an issue always.
I did not managed to track when and why the menory usage grows yet.