(Hoping this project is still alive!)

Out of curiosity, were you playing on normal difficulty or Mega Monkey?

Yes, congratulations are in order, as rodo's port works great on my modded Wii (Wiikey+SD Gecko+1GB Sandisk SD). The lag is negligible, though I am experiencing about a 2-3 second lag on COMI (MI3) using compressed OGG sound. It usually doesn't affect gameplay itself, except during sound and timing ...