Now that we have stuttering sorted I do have another issue to report that I hadn't bothered reporting until now.

Whenever I start playing something I get a click or thump (much like the sound when plugging/unplugging something into an amplifier that is turned on). It only happens however in when it is a user commanded action and also doesn't happen on pause/unpause:

start a new track or playlist: clicks
move to the next track in the playlist using next track: clicks
allow the next track to play after the current one finishes: no clicks
pause: no click
unpause: no click
stop (hold pause on Squeezecenter Controller): no click
restart from stop (press pause): clicks

Sometimes there is a single click, other times there are two clicks, can't work out the pattern of when there is just one click.

The clicks happen no matter how I control the player (front panel controls, Squeezebox Controller, SqueezeCenter).