Finally, I turned my attention to the iPad itself: I selected to power down and restart the iPad. I had some unexpected difficulty here as well; I needed to do a forced restart (holding down the Sleep/Wake and Home buttons simultaneously for around 10 seconds) before I could get the iPad to progress to the Lock screen.

The good news is that this did the trick. When I next went to iTunes, the iPad backed up and synced without a hitch. Numerous users have reported the same and most have had similar success after an iPad restart.

All has proceeded normally on subsequent sync attempts. I’m still not sure precisely what precipitated the problem, but at least I now know how to fix it.