^^ you may have to hunt down the cIOS stub, or GX may do it for you?
try scrubbing all custom settings back to factory defaults, or a clean install.
and back on the disk, i overlooked some of those shits have sneaky da$hboard updates (faschbaord) but the game can be loaded still by denying the req.
also, uslbloaders of most kinds can boot a retail disk as if it was the legit wii frontend anyway.
again, refer to the GX settings, and have it bypass any updates from the disk and/or installed game.
...
you will know if it's a da$h update req, nuke it.