Nice to know for sure, thanks for looking that up dave.
All you had to do OP:
1. Hack the 4.2 following a guide here.
2. If you really wanted to go to 4.1, install IOS60 v6174 (and make darn sure it installs), then install System menu 4.1 for your region (but this is not needed, 4.2 works fine).
And again, DOP-Mii would have checked to make sure you have that IOS installed. The Point is you should have followed a guide here
Bad_Ad or Erikie can fix your Wii with either boot2 or the nand.bin.