This is probably a classic but here goes. Some time between midnight and three my 9 month old will wake crying. Often he is hungry or has gas and can be fairly easily consoled and falls asleep in our arms once his needs have been met.
However, on many occasions, no matter how long we wait or how deeply he appears to be asleep, the instant he "touches down" on his bed (or sometimes a few milliseconds before), he will arch his back and begin to cry. After that there is nothing to do but to pick him up again and he will frequently fall right back asleep in our arms.
What's up with that? Is it time we take the shards of glass out of his mattress? (just kidding - I'm tired and feeling a little punchy).
When he first falls asleep for the night the Devil's orchestra couldn't wake the little sack of potatoes, but once he transitions to REM stage we go through this circus act. Not every night - some nights he will sleep straight through from 8:30 till 6:30. But on the "bad nights" we might be up for a couple hours doing the "putting himdown" song and dance.
I guess I want to get some opinions on "how the heck does he wake up instantly the moment he touches his bed?" and "why?" before moving on to what could be done.
Update
I'm answering my own question 4 years after the fact because I had the recent opportunity to think back on this and wanted to capture those thoughts.
Eventually things worked out. It was many months, but sleep habits formed and everyone ended up getting their much-needed rest. In the meantime, here's what worked:
Reduce the % change in environment.
Basically, I tried to make sure that there was as little change at once, with pauses in-between. This translated to a fairly drawn out process, but anything was better than being up all night. In order to reduce the % change, I had to add a bunch of stuff that could be kept constant. Noise, lighting, temperature, etc. because of course physical contact and orientation were going to change as soon as I put him in the bed.
Noise: create a white noise environment that will not change when you put the child down - be aware that the sides of a crib can alter the frequencies that hit the ear, so be mindful of your sound source and how it sounds above the bed (where you'll be rocking the child) and inside the bed.
Humming: add your own noise (humming or singing) to the mix. This is a good one because it maintains your presence, and (more importantly) can be tapered off gradually (sing quieter and quieter)
Light: be mindful of how any ambient light can be occluded by the sides of the crib - and possibly register on the child's eyelids. And don't forget your own shadow.
Orientation: you need to gradually move the baby into the exact orientation (in your arms) that the child will be on the bed. So figure out how you need to hold the child when being laid on the bed and maneuver him/her into position in your arms. Cribs with deep sides are killer because you have to really bend over and that can mess up your back. Don't let the child roll when you lay them down! Be prepared to stay leaning over the crib with the child still in your arms, but touching the bed for agonizing periods before you remove your hands / arms, which changes body heat
Body Heat: blankets and swaddling are key here as they insulate the child from y our own body heat and there's less of a temperature drop when you extract yourself.
Don't leave yet! If by some miracle you've extracted your hands, stay where you are! Keep everything else constant - your humming, the white noise, the light, and your presence.
Ninja-like exit. Practice your exit - two steps max if you have creaky floors. I had it down to two steps, a pivot and close the door in under 2 seconds. When you're ready to go for broke and you've followed all the other steps slowly, get out of there in a (soundless) flash.
Repeat, repeat, repeat. Ritual is the key. The more you do everything exactly the same, the more smooth the process will be.
Stay calm. Agitation is the worst. You know those nights you REALLY just need the baby to settle down because you have to get some work done, or go out, or just get to sleep? That's the night it will take THE LONGEST! So just be calm. I got to a point where my inner monologue was "hey, enjoy it. You get to be with your baby just the two of you. These are precious moments. Besides, what else am I going to do with my time? This is what I was made for..." I'm not sure I bought my own propaganda all the time, but, 4 years later I can still look back at all that with fondness so I can only conclude that A) it WAS actually precious and special and rare and B) you forget the bad stuff and remember the good - as do your kids - and that's why the human race has not died out.