The results really aren't surprising, Dinahmo. If you think about it, you have 2 parents, 4 grandparents, 8 great grandparents, 16 gt gt grandparents, 32 gt gt gt grandparents, 64 4 x grandparents, 128 5 x gt grandparents, etc etc. There are approximately three generations a century, so after five centuries, there are thousands of ancestors. It is highly unlikely that during that time, there won't be a few "foreigners", which will show up in genetic testing.
We are all descended from a handful of people many many years ago.