I know that it's possible, but I am not doing all that just for one lens. I can just shoot Canon glass on the 20D and do nothing. I also have a 5D and the lens works fine on that body.

I was just curious if anyone else has seen this before or had similar issues.

The 20D will soon be the matching paperweight to my old Rebel anyway.

I am looking at both the 30D and XTi as a second digital - just haven't decided which one yet.

Quote - Is it possible to go back to the old firmware and reinstall the newer version... Please remove the lens from your camera before performing this update.

After completing the update, turn the camera off and remove the battery for at least two seconds.

This will cause the camera to recognize the new firmware.