Why are some of the files shown as unequal excluded automatically when I exclude all equal (by content) files?

[dirk-o]

Why are some of the files shown as unequal excluded automatically when I exclude all equal (by content) files?

So, when all 10.752 files shown as equal by content ("Two way") are included, 2.045 files are displayed being unequal by content. When I exclude all of the equal files, about 30 unequal files remain included, the rest now is excluded. Why is it like that?