Still hard to isolate this problem, but - whatever I do with the power settings - it seems like it is exacerbated when I am using more than one application.
Alternatively, if I close everything down and play just say, Foobar, for example I seem to get less skipping and sputtering.
Does this suggest a "kernel mixer" mixing problem?
I hope it is not too much to ask that I would like clean, clear, sputter free audio, whether I am listening to music or to Windows sounds.
Thanks for any updates.