So the aerodynamic centre is the location where the lift due to incidence acts and is independent of incidence (more or less).
Hi CliveL,
As D120A already pointed out, there is a moment Cm0 in the aerodynamic center. This in turn implies that it is not exactly the point where the Lift is excerted, otherwise you wouldn't have a moment at this point. Normally the aerodynamic center is somewhat in front of the Center of Lift (i.e. Center of Pressure). The pitching moment of Airfoils usually increases with increasing AoA.