Canon has today issued new firmware for the EOS-1D Mark II (ver 1.2.6), EOS-1D Mark II N (ver 1.1.2) and EOS-1Ds Mark II (ver 1.1.6). These updates deliver the same improvements to all cameras, support for SDHC cards of 4 GB and more as well as correcting the detected capacity of Compact Flash cards of 12 GB and more. These updates can be installed by the user by simply loading the update file onto a storage card and selecting the firmware update option from the camera menu.
Click here to download firmware for the Canon EOS-1D Mark II
Click here to download firmware for the Canon EOS-1D Mark II N
Click here to download firmware for the Canon EOS-1Ds Mark II
via dpreview.com