I have searched and googled and cannot figure this out.
My 4.5 and 6 yr old sons were playing the Wii and got a little ambitious. They figured out how to send some of the miis to the mii parade. From there, when they went to wii fit, some of the mii's permanently changed appearance. I went to the mii plaza and changed the affected miis back, put birthdays back in and turned mingle off. I went back to the wii fit and all mii's were restored. This morning, the miis changed again in wii fit....but are unchanged in the mii plaza. I have powered down, that didn't work. The mii that represents me in Wii Fit still is me, has my data, but is the appearance of one of the Guest Miis. I decided to add a new mii to Wii Fit, my mii is available, so I added my mii back. It did say that if my mii was not available it would use a guest mii (this is where I think the parade comes in....however, I took the miis out of the parade).

Frustrated, I finally deleted the wrong miis from the Wii Fit plaza. Unfortunately, my wii fit data is now lost, it was only 3 weeks. I warned my kids to stop playing around with wii....but in case this happens again, does anyone know what the heck happened? Was there a way I can save my mii? Or was this just a weird glitchy thing? BTW, even a locked wii fit mii was affected.