Please Note i did not choose the song it is playing randomly BUT the issue did show its ugly head!!! have a listen NO COPYRIGHT INFRINGMENT INTENDED!!!
Have you tried running without the NAS? If it works without the NAS then you will know where the problem lies, otherwise we can remove that from the equation.
If the audio is jittery it could be an indication of an audio driver issue.
Thanks Jason! it is the Audio Driver/Soundcard Causing the Fault, thankyou for the Help From Nathan In Australia