  Mega et al.(cond-mat/0212529) proposed to use the ``diffusion entropy'' (DE)
method to demonstrate that the distribution of time intervals between a large
earthquake (the mainshock of a given seismic sequence) and the next one does
not obey Poisson statistics. We have performed synthetic tests which show that
the DE is unable to detect correlations between clusters, thus negating the
claimed possibility of detecting an intercluster correlation. We also show that
the LR model, proposed by Mega et al. to reproduce inter-cluster correlation,
is insufficient to account for the correlation observed in the data.
