Canon has released a firmware update for the EOS 5D Mark II and EOS 50D.
The Version 2.1.2 firmware being released this time is for cameras with firmware up to Version 2.1.1. If the camera's firmware is already Version 2.1.2, it is not necessary to update the firmware.
Firmware for EOS 5D Mark II
1. Optimizes the camera's performance when using certain UDMA 7-compatible CF cards released in February 2012 or later.The new EOS 5D Mark II Firmware Version 2.1.2 can be downloaded by clicking here.
Firmware for EOS 50D
1. Optimizes the camera's performance when using certain UDMA 7-compatible CF cards released in February 2012 or later.
2. Corrects wording in the Dutch language menu screen.The new EOS 50D Firmware Version 1.0.9 can be downloaded by clicking here.
Source: Canon USA