RDM not resizing after a while minimised...

This has been happening for a while now, if I leave the program minimised for a (long) while, it doesn't seem to restore properly (or at all if there is a password on the application). Without a password; the RDM window will restore but only partially (see attached), when you drag the window, you can see the frame of the size it should be?! I've tried Windows -> Reset Layout too...