Happen to work in retail where I was given the display DSi.. it will not power off for anything. I know it is not something broken on it. The rep told me they are all that way. Maybe it is something physically built into the display units where you can't power it off, but I can't find any evidence on the net of this. Find it hard to believe Nintendo would manufacture different models so the power could not be turned off. Maybe it's something in the firmware? I updated firmware to 1.4.3U. Still won't power off. Does anyone happen to know?