  Some recent studies exposed rather strong statistical evidence of
in-vacuo-dispersion-like spectral lags for gamma-ray bursts (GRBs), a linear
correlation between time of observation and energy of GRB particles. Those
results focused on testing in-vacuo dispersion for the most energetic GRB
particles, and in particular only included photons with energy at emission
greater than 40 GeV. We here extend the window of the statistical analysis down
to 5 GeV and find results that are consistent with what had been previously
noticed at higher energies.
