I take your point Gunnar, but does the check system on the KN7000 examine every single byte of the new software? Checksums can be wrong - I have experienced this in the past.
If you download an upgrade for a PC, and install it and then find it is faulty, at least you can revert your PC back to it's original state, either by re-installing the original software, or in XP, by using System Restore. I have known occasions when people have downloaded BIOS upgrades via the internet, installed them and ended up with a 'Dead' PC and that ain't funny
If you install defective software in your KN7000 there is no system restore and you don't have the original software.
I would imagine that the discs supplied by Technics undergo a Byte for Byte comparison check with the original, to ensure their integrity.
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Willum