Where is this battery draining code from?

Hmm, that's an odd one. I just tried here on a power meter, and the power draw when displaying a message was 2.5mA, where normally you'd expect 0.25mA

And actually opening a message then going back to the messages list raised it slightly - by 2.5mA each time! I've just had a look at timers and it would appear to be something related to the buzz pattern, which we have seen in logs before. I'll try and have a look at it later tonight - it's good I can reproduce