Each year I have a couple of hives with brood in supers this time of year, above the QX. Obviously the first port of call is a faulty QX, but it seems to happen with different QXs. I was wondering if, in the winter queens slim down a bit and can get through, a bit like virgin Qs can? I should say that today the queen was where she should be, happily below the QX, and there were no fresh eggs in there, but she's obviously had an excursion up there coupler of weeks ago.