My first attempt at raising queens in fresh comb (Miller method) went down in flames.
1) I'm POSITIVE the marked queen was in the bottom box when I put the queen excluder on. I found her on a frame and put that frame in the bottom box before I put the excluder on.
2) I'm CERTAIN the excluder was put on square, and since it's rarely been used, there weren't any bent wires or anything.
2) I'm CONFIDENT the upper box was queenless after I slid the cloake board panel in, because they were roaring loudly when I opened it up a day later to put the frame with new brood in. A day later (Friday) I pulled the panel out
So when I opened the box up to check the brood frame, what was the first thing I saw on it? My marked queen. Laying eggs in the comb, which the bees had re-drawn out beyond my cut-outs to fill the frame almost completely. All sign of my previous day-old larvae was gone.
This queen is an odd one. I got her with a package last year, and she is long and slim, not plump at all. I guess I should have figured she'd be able to move through the excluder when she wanted to. But she's been a prolific queen; that first-year hive gave me 55 lbs of honey last August. And it wintered well with and is now at 2 boxes full of bees, which is why I chose to use it for my finishing hive.
So I split the hive instead. Moved the queen off the frame with new eggs and put her in the walkaway. I'm POSITIVE she's in there.

The frame with new eggs when into the now-queenless cutdown; there's already lots of brood in the day 1 & 2 stage in there.
At least I can get some queen cells from the cutdown to make up nucs in about a week and a half. All the best laid plans . . .
-- Kris