now i'm a little bit more confused.
I have 4 QlineEdit all with lostfocus signal conected to a slot (for each QLineEdit a diferent slot).
in each slot i put a line of code that display a text like "i'm in the slot x" - debug of course

so each time i open a new window the QlineEdit lost its focus... OK
i left the cursor each time in a diferent QLineEdit (each time the focus was on a different QLineEdit). When I've opened a window the box lost its focus ... OK
In all described cases i have never changed the text.

then i add a line of code: if (!box.isModified()) return
i've put the line before the debug text

i've repeat all over again. AND the result was... Just in one QLineEdit the flag modified was true. WHY? am i missing something? is there a propertie to define?