Well, sound was preventing it to go further 
There's actually quite a few games based on sound events, obviously, if sound isn't working right it's likely that it won't work, so it basically wait for either the sound to start or the sound to stop to do an action, as going to the next race in MKDD, going to the next level in Pikmin 2, or even be able to press A when you gain an item in Zelda :p
It was fixed sometimes ago already, take a look : http://code.google.com/p/dolphin-emu/source/detail?r=3392
And don't forget to thanks Luigi
There's actually quite a few games based on sound events, obviously, if sound isn't working right it's likely that it won't work, so it basically wait for either the sound to start or the sound to stop to do an action, as going to the next race in MKDD, going to the next level in Pikmin 2, or even be able to press A when you gain an item in Zelda :p
It was fixed sometimes ago already, take a look : http://code.google.com/p/dolphin-emu/source/detail?r=3392
And don't forget to thanks Luigi