zenmonkey wrote:Back up the media (Anki back-up does not back-up the media library)
The answer to your issue is going to breaking that out to different users and decks.
How many decks do you currently have? One per language?
The AwesomeTTS media is created on-the-fly, and I think I've chosen not to save the files after Anki is closed. I might be wrong, but I don't think that a folder with thousands of media files was the main culprit, but rather that the setting itself (e.g. the code snippet which creates the file and plays it back automatically) was already too big a change for the template(s) affecting a large number of cards. I remember having problems last summer by just adding one new deck with a low number of cards (say, fewer than 50), and no audio.
I have nine or ten decks, but since last year (when I encountered the sync problems), I don't add anything else but cards to the decks that are already working.