Replaced CDP w/ Transport; Now, Soundstage Changes Dramatically w/each CD. Why?


Here's something I've never encountered. I've borrowed  a Heed DT Transport and am loving the increased resolution, compared to my Jolida JD100 cdp BUT, now the sound-stage expands and contracts, depending upon whichever CD is being played.The effect is very evident-- not subtle. This is really weird. 

System: Heed Transport -> Aqua La Voce II DAC -> Wells Majestic Integrated -> Silverline SR17.5 Monitors.
 
I don't even know where to begin. . . any suggestions? ? ? 

BTW, replacing the Blue Jeans BNC cable with an Empirical Audio BNC cable didn't change anything. 
stuartk
Regarding the fluttering disc: I use a rubber mat designed to be placed on top of the disc when playing. Noticeably improved sound. 
Question, why you think CD vibration would hurt the sound? I mean, after all the player has error correction and a laser Servo Tracking system, no?
geoffkait: it's a claim I've read repeatedly by those who advocate burning CDs to a hard disc and by those manufacturers, such as PS Audio, that sell players with memory buffers.
geoffkait: then perhaps I misunderstood you. Can you re-phrase the question?