Thanks for the note. Yes, I am aware that user content can't sync to mobile devices via wi-fi if dropbox sync is enabled. The problem occurred before enabling dropbox sync. Everything was fine in version 10.3.1, but immediately upon installing 10.3.2, and without dropbox sync enabled, only purchased content would sync, and personal data would not. I went a few rounds with tech support and they could not solve it. Basically, the sync would abort with the error message as stated above.
Since then, I enabled dropbox sync, and user data I entered on my Mac syncs to both my iPad and iPod touch, and purchased content & updates continue to sync through 'sync with mobile device', so I am able to get everything synced, though with an extra step (which is ultimately not a big deal). The problem could possibly be with my MacBook, whose keyboard failed a couple months ago, and now I'm using an Apple bluetooth keyboard. However, the sync problem was not there with the external keyboard and Accordance 10.3.1.