Hi everyone! I decided to post this question in the PN forum before I go and pay 50 euro for asking the same at the Canon Service. I was shooting an event on Saturday with my 40D + 580EX II when the battery ran out on the flash. I took it off to reload the batteries and in the mean time take a few shots using the camera's built-in flash but it would not open. I went into the settings menu only to find that the probable cause was that the camera had registerd that the external flash is still on! Anyway, to make the story short, I finished the shooting (with the external flash) and afterward tried several times to open-close the camera and flash but the Menu Setting stayed permanently set as if the External Flash was on. Has anyone had a similar experience? Any suggestions, aside from the obvious 50 euro visit to the Canon Service?