From Canon Europe:
FAQ: EOS-1D C Latest Firmware Update [Version 1.2.0 - Added 29 May 2013]
Details:
Firmware version 1.2.0 incorporates the following improvements and fixes:
Note:Items No. 1,2,4,5,6 and 7 have been incorporated into Firmware Version 1.1.9.
Items No. 1 through 7 have been incorporated into Firmware Version 1.2.0.
Helpful Information:
Firmware Version 1.2.0 is for cameras running either Firmware Version 1.0.2 or Firmware Version 1.1.9.
Solution:
Customers who wish to update EOS-1D C to Firmware Version 1.2.0 are requested to bring their cameras to our authorised service facilities.
Support will begin on 29 May.
If you have any further enquiries, please contact us using the e-mail support or telephone support option.
B&H carries the Canon EOS-1D C camera.