The system of equations
u_t + (\partial_x^2 + \partial_y^2)u_x + u u_x/2 = -(p_x u_x + p_y u_y)/2 (Eq. 1)
p_xx + p_yy = u_x (Eq. 2)
reduces to the KdV equation if u and p are independent of y. The KdV equation can of course be solved using the inverse scattering transformation (IST). Can the system of equations (1) and (2) be solved by the IST when u and p depend on x, y and t? [These equations arise in the theory of electromigration in thin films --- see R. M. Bradley, Physica D 158, 216 (2001)].