Canon EOS 20D Firmware Update
Canon has already released a firmware update for the new 20D. If you are one of the ones that bought it as soon as it hit the shelves, you might need the update. The new version is 1.0.4.
This firmware update (Version 1.0.4) includes the following two changes:
1. Fixes the problem of the shutter release not working.
2. Improves reliability when using some Compact Flash cards.
Currently their firmware update service is down, but check back at Canon later on and hopefully they’ll have it up and running.