I got it working the other day through some advice from gekka_no_kenshi, so all credit goes to him:
"the wii seems to be selectively blocking certain headers of gc discs to prevent them from booting (like AR). changing the header can bypass that (u'll need a modded wii also to run the burnt disc). first, make an image of the disc. then use something like a hex editor to see the header of the image. it's like the first 20 bytes or so. it'll be something like NHL.. something. replace that using a valid header from another working gc game. i used the header from the paper mario disc. make sure u're only replacing bytes, not adding or deleting them. when u're done, save the image, and then burn it. load it in the wii, and it should work perfectly."