(except at that point it was to upgrade to 4.0, not 4.1)
So all was fine until I tried to play Wii Sports Resort.
I was getting the "An error has occurred. Press eject button and remove the disc, then turn the Wii Console off and refer to the wii operations manual for help troubleshooting" message.
cIOSCorp is never the way to go. If you search you can find a few cIOSCorp uninstallers and that may help you. Not sure either but try getting 4.1 system menu, use waninkoko's, the link is in my signature.