Turning off photo syncing, resyncing (which deleted the photos from the iPad), and then turning on photo syncing again and copying all photos back to the iPad got Faces back in alphabetical order.
I'll post again if it gets corrupt again.
Still - has anyone else run across this issue and/or a faster (or iPad-only) solution?
Count yourself lucky. I haven't been able to get Photos to sort Faces properly even after turning off photo sync, verifying all photos were deleted from the iPad, and resyncing all 3300+ photos. iPad starts with "Chris," runs up to "Yasmin," then has "Adrianna" through a different "Chris" to finish things off. This is with all the latest updates, iTunes and iPhoto on the Mac side, and iOS 4.3.2 on the iPad.
I suppose it's harmless enough, but it is stupid and will look very foolish to anyone I show photos to. Sorting is pretty fundamental, and a gaffe like this does not inspire confidence.
Karl, has your issue ever come back? I have had the same issue for months now, on both my iPad 2 and iPhone 4, and sometimes its A-Z but mostly its not. Seems to start at "Debbie" alot and then go Z to back to A downward. Currently its now starting with U's for me, very odd!! I will try your remendy and see if it stops it for me. thanks