uhm... yeah... i have sigmatel audio, and sound doesnt work in ubuntu. last time i had installed ubuntu, i got the sound working, but i dont remember how to do it... right now all i know is that i cannot hear anything, and my sound card is no longer installed (the volume control says "No volume control GStreamer plugins and/or devices found.)

ive been following this tutorial, but when i get to the un-tarring it doesnt work:
Sigmatel Audio Card Driver - Ubuntu Forums

any help? i really want sound for Halo and Pidgin and everything (youtube!)