Two of my SACDs that have this warning are on the Telarc label (Al Di Meola's _Flesh on Flesh_ and Ensemble Galilie's _From the Isles to the Courts_). The disc surface definately looks different on these.
I thought I remembered the instruction sheet for Auric Illuminator saying not to use it on Sonopress SACDs. Unfortunately, I can't find it the sheet.
My _Dark Side of the Moon_ SACD does not come with the warning but has a similar looking surface, which made me wonder if it has the same fragility issues.
Hooper: I used to get scratches with MS as well. But I realized it was the polish pads, not the product itself, that was causing the scratches. So now I just spread it around with the moistened end of my index finger. No more scratches.