Re-Virginize Your Wii

[Vega]

I was going to say it's because the re-viginization changes your Wii ID and clears out your DWC_AUTHDATA, but nowadays Wiimmfi has a different way to identifying the Wiis (certs of some sort iirc). So the re-virginization is modifying something with these certs. That's my uneducated guess, you might want to ask somebody on the Wii-Homebrew forums.