Dynamical response function of the disordered kinetic Ising model

Recently Baumann et al. [arXiv:0709.3228v1] studied the phase-ordering kinetics of the two-dimensional Ising model with uniform spatially quenched disorder by Monte-Carlo simulations. They found that the two-time response and correlation functions are in agreement with the predictions of local scale invariance generalised to z!=2. The present paper shows why this is not true and suggests an alternative approach which leads to a much better agreement with the numerical results.