Yeah, I was really pumped up when I heard the latest Gecko finally offered GCN support. It booted up Pokemon Colosseum (JPN) just fine, but it produced a code dump when I put in the Extension Disk (right before it normally verifies the options you selected, like Ocarina On or not, Force NSTC, etc.).
I haven't extensively messed around with the options yet, but I chose:
Language: Japanese
Force NSTC: Yes
Ocarina: No
Everything else was left off.
If someone could get this to work in the future, I can finally dump my old Gamecube and sell my soul to my Wii. ^^