I've had my Wii for about 2 weeks now and now I occasionally get this message when I start it up: "The Wii System files are corrupted. Please refer to the Nintendo Wii Operations Manual." I then restart it and it works fine. The error mainly happens when I'm in the message board or just before the main menu loads up at the start. Is this a defective unit? Can an update (don't have wifi yet) fix the problem? Do I need to get a replacement unit? Does anyone else have this problem or have any advice?