You have an old 9S front derailleur (on the left).

As Campagnolo and now you found out, it will not reliably shift a 16 tooth difference (which is why the early square taper compacts came with either 50-36 or 48-34 rings)

Either get the proper 10S compact derailleur (on the right) or a post 2009 10S derailleur.

That should eliminate 99% of the problem.