if one changes part assinments etc, then don't save but go into pcb edit and press ok, all you changed in previous view ie all your feeder to part assinments are lost.

but why should you revert changes if I keep modifying the same project?! That is definately very counter intuative, and very common, if I just want to add so we have a panel in the PCB all my feeder assignments shouldn't be reverted...