Jet lag doesn't seem to be a problem; the kid takes about three days--like the rest of us--to adjust her schedule, both coming and going (we were trying to get her back on schedule, and had two major wakeup-feedings, then one, then none, during the night).
No, the problem is flip-flopping. Not the kind we hear about in the battleground states, the kind where, now that the kid has learned to roll over, she rolls onto her stomach as soon as she's on her back.
She may fall to sleep on her side, then roll over, and wake herself up in frustration 10 minutes later. We had to get up 10 times, easy, to flip her back. Finally, at 4:30 I wedged a stuffed toy against her hip to keep her from rolling over. What else do you do, tape a tennis ball to her stomach?
[Sure, this is just a phase, but I'm getting the sense that the next two years--hell, the next 20 years--are going to be an endless series of phases.]