It sounds like you don't have IOS 58 installed. Having tried GCN and Wii games from burned and USB backups, I can tell you USB is the faster method. If you're soft modded, post a SysCheck so we can see if the mod is current/done right. If you're hard modded you'll have to wait for someone with experience in hard mods to respond.
If I spelled something wrong, I'll just blame it on auto-correct