  We investigate the impact of non-linear corrections on dark energy parameter
estimation from weak lensing probes. We find that using halofit expressions,
suited to LCDM models, implies substantial discrepancies with respect to
results directly obtained from N-body simulations, when w(z)\neq-1.
Discrepancies appear strong when using models with w'(z=0)>0, as fiducial
models; they are however significant even in the neighborhood of LCDM, where
neglecting the degrees of freedom associated with the DE state equation can
lead to a misestimate of the matter density parameter \Omega_m.
