  The observed magnetic spin susceptibility of high-temperature superconductors
such as La$_{2- x}$Sr$_x$CuO$_4$ increases when $x$ increases from zero, i.e.
as one dopes away from half-filling. Recent Monte Carlo simulations of A. Moreo
(Phys. Rev. B {\bf 48}, 3380 (1993)) suggest that this behavior can be
reproduced by the two-dimensional Hubbard model only at large coupling, namely,
$U/t$ of order $10$. Using longer runs, our Monte Carlo simulations show that
the same behavior as for $U/t=10$ is obtained even in the intermediate coupling
regime ($U/t=4$), as long as the temperature is low enough ($T=t/6$) that
strong antiferromagnetic correlations are building up at half-filling. These
results are consistent with the fact that in two-dimensions, the GRPA should
fail in the parameter range where it predicts a magnetic phase transition.
