Hi, I´m getting 35-45minutes out of my PBG4-400 nowadays, down from os9 4h and OS10.1 2,5h. Is this likely to be a sw-problem rather than an old-battery one? Arent Li-Ion-batteries supposed to be eternal?.... I´d like to hear your opininions as I wouldn´t want to by a new battery just to get 45 minutes out of that, too. Anders