Lost sound control after yesterday's updates

[Nigel Ridley]

Dell Inspiron 1525 running Jaunty.

I updated my laptop yesterday which included the new kernel (2.6.28-13-generic) and I have now 
lost the ability to adjust the volume control by either the touch buttons on the laptop or 
scrolling whilst hovering over the speaker icon on the panel.
I can only adjust the volume by opening KMix and using the sliders.

Does this affect other users of different hardware, or is it specific to the Inspiron 1525?

Blessings,

Nigel