treelist didnt populate

[ditsikts]

How to test: run app, go to Employee->insert , add an employee
push "insert data" and add some data with different dates.
you notice that populate treelist works fine.
Problem is when I use search.
So "tick' for enable search groupbox use dateEdits and click search, you ll see that didnt show anything.
Is weird, because first 3-4 times works fine