[dnanian]

You definitely shouldn't copy a case sensitive drive over a case insensitive drive, because you can have files that can exist side-by-side on the source but not on the destination (e.g. files with the same name but case differences).

But, certainly, we never touch files on the source except to read them. If you're missing files on the source, it happened outside SuperDuper.

Not sure why your source would have 10GB 'extra' data. Is it your startup drive?