Canon have just released this update which when applied to the camera will improve performance with UDMA 7 type cards. There are other bug fixes too so its worth doing.
Version 2.0.7 is now available (the last released one was 2.0.4)
This fixes a few bugs including one I noticed myself (strange aperture movement in movie mode when using a macro lens).
I have just updated my camera to the latest version of the firmware available from Canon (as of yesterday).
Its version 1.1.0 and the main improvements are in the movie mode, basicaly you now have control over asa, aperture and shutter speed.
This was a much requested feature (the camera was auto everything before this – with no easy way to control any variable).
Previously the popular way to control aperture in movie mode was to use Nikon lenses on an adapter, this may have been noticed by Canon…..
If you do shoot short movie clips when on location (a good idea) then consider the upgrade, if not then read about the changes first then decide if you want to update, you can read and download from here:
Clients with these cameras may wish to download the updates. The updates involve minor fixes as well as improving the brightness of the preview display. You can read more and download the firmware by following these links:
Version 1.0.3 for the Canon 5D
Version 1.0.2 for the Canon 1D Mk2n
Read the instructions for using the updater very carefully, especialy about having a fresh battery or the mains adapter attached, you dont want to have the power on the camera shut down in the course of the update. If you wish I can perform the update whilst next on site.