Since installing Mavericks the remaining % on the inbuilt battery icon will occasionally stop counting down, it will just sit there not updating. It stays like this until I open Energy Saver prefs and remove and re-tick 'show battery status' - then it updates and shows the correct %. iStat (minus the usual 5%), Coconut & Battery Time all show the correct info that would have normally matched up to the menu bar battery % but it no longer does. So it does just seem like the the menu bar item is not updating as it should. I've tried an SMC reset and a PRAM reset (I now know the PRAM wouldn't have helped anyway) but to no avail. Macbook is 3 months old. Any ideas ?