Your nand is jacked. If you want to look at a possible cause make a new nand backup of the briced wii. Then run nandbincheck on the bricked nand.bin. It may point out a possible cause of your issue.
nandbincheck can be found here- nandBinCheck (Wii Entry -- PC Software) - GBAtemp.net
just do from shell-
nandbincheck nand.bin -fs -all -v
You can use the formater, but I would use ohneswanzenegger, found here- ohneswanzenegger (Wii Entry -- PC Software) - GBAtemp.net
Use this nand.bin formater to format a copy of your new bricked nand.bin
Then install 4.1 with the formater, setup the setting.txt
Run nandbincheck on the new nand.bin and ensure all looks good
Then restore your new nand.bin, you should have a nice clean wii
Softmod again with my guide.
Make sure your using semi up to date loaders
If you like you can post the nandbincheck here of the bricked nand.bin for shits and giggles. I won't have much to say about it, but would enjoy looking at it.
As for your ios failed to load error. This error is caused when loading cboot2 and no ios36 and under are working.