Any a900 users had issues with their rear of unit on/off switch? Mine ' failed' last year after approx 6000 shutter actuations. Sony Service ( the only people who have access to Sony Spares in Oz) charged me $350.00 AU and effectively replaced the entire back section of the camera. All that was 'wrong' with the switch was that the central actuator shaft (plastic) had broken. One might have thought to replace such a simple component would not have entailed replacing the entire back panel including LCD. Admittedly Sony Technicians did a great job...the Camera has never worked better...but fair enough for the price!