Qt for Python (PySide/Shiboken)

hi, is it possible to "keep alive" QtObject properties from dynamic created windows? I store a QtObject in a property in the new window, and store a reference to the created window in a list in the parent window, however, if I create another window after the first one (without exiting the first window), I can't access the QtObject in the first window anymore, I get null when accessing it.