Having same problem here.
But the weird thing is, when I tried to install "Mint 8" for the first time,
sound worked and that was unbelievable so I rechecked it on Youtube, so it really worked before!
( Cause non of the linux distros gave me sound output on "Toshiba nb205" without painful terminal works )
Sadly, I didn't installed it that time. I saw a blog post that "Mint Fluxbox" is better than the regular
so I wiped out the USB, which was containing the original "Mint 8"
Anyways, after that, I made USB-live-cd over than 10 times, but I couldn't hear any sound anymore