I thought it might be worthwhile to start another thread on this. I use my SP4 a lot during the day visiting customers. I close the lid, put it in the leather case and drop it in my car when finished. I find sometimes, but not always, I will take it out again at home or my next appointment to find it obviously hot, not dangerously hot, but it should be sleeping, not running flat out and running the battery down. I have all the updates installed. I read about this problem before and I had assumed that it was all sorted, but it seems not. I'm thinking from now on I should just shut it down instead. Any thoughts?