  In cond-mat/9907125 the low-temperature behavior of a model for RNA secondary
structure was studied. It is claimed that the model exhibits a breaking of the
replica symmetry, since the width of the distribution P(q) of overlaps may
converge to a finite value at T=0. The authors used an exact enumeration method
to obtain all ground states for a given RNA sequence. Because of the
exponential growing degeneracy, only sequences up to length L=256 could be
studied.
  Here it is shown that, in contrast to the previous results, by going to much
larger sizes as L=2000 the variance coverges towards zero, i.e. P(q) is a
delta-function in the thermodynamic limit.
