This gentleman is inquiring about how time machine decides to delete files. He has some pretty extensive logging to back up his question/quandry. Here is a link to our discussion, I'm out of my depth on this one.
Whew, good work on both your parts.
I wonder if TM is determining that all the files in the deleted backup exist in another backup?
Then there's the question of SuperDuper & other manipulations that may affect GUIDs???
Retrieving data ...