  Adopting the mean-field composite fermion picture, we describe the
magneto-transport properties of a two-dimensional electron gas with laterally
modulated density around filling factor 1/2. The occurrence of a strong
positive magnetoresistance at low effective magnetic fields as well as Weiss
oscillations, which were observed in recent experiments in such systems, can be
explained within a semi-classical Boltzmann equation approach, provided one
goes beyond a second order approximation in the modulation strength.
