  During the pre-Swift era, a clustering of light curves was observed in the
X-ray, optical and infrared afterglow of gamma-ray bursts. We used a sample of
254 GRB X-ray afterglows to check this fact in the Swift era. We corrected
fluxes for distance, time dilation and losses of energy due to cosmological
effects. With all our data in hand, we faced with a problem: our data were
scattered. We investigated 3 possibilities to explain this, namely: the
clustering does not exist, there are problems during calibration of data, and
there are instrumental problems. We finally confirm that our sample is
consistent with Dainotti correlation.
