The kicked quantum rotor (a particle freely moving on a circle subject to periodic delta-kicks) has been studied for decades and is one of the most popular models of quantum chaos. The dynamics of the classical version of the model corresponds to the diffusive random walk in the angular momentum space and constant energy absorption. The quantum dynamics exhibits a phenomenon of the dynamic localization (suppression of the classical diffusion by destructive quantum interference), as was discovered numerically by Casati et al. in 1979, and was believed to be proven analytically in 1996 by Altland and Zirnbauer. I would like to discuss a very recent preprint by Tian, Kamenev and Larkin (cond-mat/0403482) which reexamines the question of quantum corrections to the diffusion, and brings to light certain effects apparently missed by the approach of Altland and Zirnbauer