I'm having a very strange problem with sound in ubuntu. When i turn up and down the system volume it doesn't work properly.

Everything sounds good with the volume at max level, but when i turn it down using the multimedia keys, it seems to only reduce volume in the right speaker, and the left speaker starts to sound a lot more woolly, or bassy. I dont notice a gradual reduction in volume in the left speaker until i switch it all the way down to 0. Also muting doesnt work properly. There are no problems with turning volume up and down inside individual programs.

The soundcard i have is by SigmaTel audio. I've had a look through the comprehensive audio solution thread, and i've tried to uninstall and reinstall the sound packages, but no luck.

Can't help thinking its something to do with pulseaudio/alsa, because i didn't have the problem in Gutsy, but i don't know a lot about either pulse or alsa. Any advice to give me a clue as to where i should start looking for solutions would be greatly appreciated, because i'm stumped right now.

thanks guys...