I'm setting up a friend's HP Presario (quite old) laptop with Ubuntu 12.04 which used to work fine in 11.10. However, the volume is completely silent until it is turned up to about 3/4. Past this point, it makes giant leaps all the way up to 100% when volume is on full.
Alsamixer, however, shows this perfectly. The 'master' bar stays at zero until the normal volume setting is past 3/4, so it's measuring actual volume perfectly. This suggests that it's a problem with Ubuntu's volume control.
EDIT - on the sound settings labelled volume slider (at the bottom), the volume seems to be zero at the 'unamplified' point (75% across the bar) and 100% at the '100%' point.