Not exactly the logic I was eluding to. The check could be completed when the power is turned on, then select the active slot even if it's configured to use the empty one.
The issue I have reported is that this check is done when the camera power is OFF...which may lead to some interesting power drain issues if the camera is left off for an extended period of time (the camera has to check for some condition when the power is off to detect the door opening). However Canon could not confirm that this impacts the charge on the battery.
Likely they wont do anything about it as it's a minor issue but a big pain in the neck for some of us.
Probobly "broken" for a long time in my opinion. I would be interested in knowing what reasonable purpose there is to have the camera switch active cards when the power is off. I can understand if you do it when the power is switched on but OFF should be OFF!
So, if you removed the CF card and didn't replace it, you'd rather turn the camera on and have it try to write your pictures to an empth card slot? I assume that's the logic.
Question for 1-series/5DIII users - what happens if you open the door, remove the CF card, immediately insert a new CF card, then close the door? Does it continue writing to the CF card?