RC,
Chris, Rab, et al,
Can't be included in this one. I'm not in the same league as some of these bee farmers so I don't get this sort of thing happening to me - certainly not often enough to take much notice!
Signs are one thing, rules are another. I'm not sure that I would go so far as Chris and say being queenright is a prerequisite for feeding success, but he has seen it a lot of times more than me...99% is OK for a rule where bees are concerned. His second post (#15) seems to indicate he means the cart before the horse and not necessarily what he said in post #13.
A bit like taking in pollen in the spring is said to be a good sign of a laying queen. If they are not, I definitely take it as a bad sign, but don't rely on it absolutely, if they are taking in pollen. This one seems to be the same - effect and cause, not cause and effect, if you see what I mean.
Regards, RAB