Counting rational points on cubic hypersurfaces

Let X be a geometrically integral projective cubic hypersurface defined over the rationals, with dimension D and singular locus of dimension at most D-4. For any \epsilon>0, we show that X contains O(B^{D+\epsilon}) rational points of height at most B. The implied constant in this estimate depends upon the choice of \epsilon and the coefficients of the cubic form defining X.