I know i am going to feel really dumb when this is answered but MC help says there are two sync modes, all and playlists. I can't see any option to change the mode at all! a tree for playlists and smartlists opens up under "Sync List" but I just want to sync the entire library. tell me i'm being stupid!
The definition of all grows over time. Now we are dealing with multi-media, not just audio. IMO syncing all may be more then the some users really want, so I think using smartlists to gain some control is appropriate for this function. I don't know if you noticed it, but MC has a standard set of smartlists that you can use for syncing and other purposes. You will see these in the tree under playlists. Go to:
Playlists-->Smartlists
Under smartlists there are many lists including:
All Files
Audio -- All
Image & Video -- All
When you set up your sync options, you can select any of these to drive the sync. Once you pick the smartlist in your options, it remembers it for next time. So if you always want to sync Audio -- All, it is automatic once you set up the options the first time.
You may already know all of this, but I thought I would pass it on just in case.