found something interesting: rootnik from uphuck.ggrn.de solved all keyboard and sound problems with the ml6720. here's what he wrote: i still need to figure out what drivers exactly he used from this forum but i'll try it out tonight. i realize your post was back in november but i thought we should keep this going for all those with ML6720's that want to get osx on their laptop.
hey tnt, i tried installing on my ml6720 using the kalyway disc, and i also had problems with my keyboard and sound. the wireless worked well, however. our audio card is the sigmatel stac 9200 and i read somewhere that they don't have support for mac osx yet. i'll let you know if i find out anything else. i, too, tried all the keyboard fixes with no success.