As reported on Rob Galbraith's website, Canon has released firmware v1.1.0 for the EOS-1D Mark III. The firmware update includes the changes of firmware v1.0.9, plus a correction for an anomaly whereby the camera won't power up after a battery is inserted, requiring the battery to be removed and reinserted.The firmware update is meant to improve the camera's AI Servo autofocus performance, provide a sharper zoomed view when playing back photos on the rear LCD, fix a bug that affects the operation of the Main Dial and Quick Control Dial and correct errors in the Italian and Simplified Chinese menus.
The update can be downloaded from here