Firmware 1.2.1available for EOS 1DX
"Canon has announced that a firmware update for its flagship EOS-1D X DSLR (Version 1.2.1) is now available for download. See below for details of the exact firmware fixes and improvements.
EOS-1D X Firmware Version 1.2.1
Firmware Version 1.2.1 for the EOS-1D X incorporates the following improvements and fixes:
The function to disable the Image size selection button has been added.
Fixes a phenomenon in which Err 70 and Err 80 may occur in very rare instances depending on the camera settings or shooting scene.
* EOS-1D X Firmware Version 1.2.1 is available to download – please click here, then enter your country and camera details and select the firmware option to download the firmware. The version 1.2.1 firmware being released this time is for EOS-1D X cameras with firmware up to version 1.1.1. If your camera's firmware is already version 1.2.1, it is not necessary to update the firmware. Please remember to read all of the instructions carefully before downloading the firmware."