Comment 2 for bug 184167

I own a Lenovo T61. Volume buttons work in Gutsy after some manual configuration: System -> Preferences -> Sound, and choose 'PCM' as the default mixer channel.

The problem appears to be that Intel HDA alsa driver doesn't export a "Master" mixer, and GNOME chooses to control "Mic" by default.

The thing with unmute not working could be a BIOS thing. Since times immemorial the Mute button on thinkpads always mutes; to unmute you'd press volume up/down.