The magnetoconductivity s(B) of a classical 2D electron crystal on superfluid4He is non-linear. Experimentally we find a contribution to s(B) which at constant field, gives s(B)8J x, the current density, while at constant current, s(B) 8 1/B. In this region the Hall velocity ¿H slowly approaches the ripplon velocity ¿I at the first reciprocal lattice vector, due to strong electron-ripplon interactions with the helium. The magnetoconductivity decreases sharply for ¿H>¿I. Fluctuations in s(B) are seen above the melting temperature.