  We investigate the effect of mesonic fluctuations on the pion propagator in
the Nambu-Jona-Lasinio (NJL) model by explicitly taking into account 1/N_c
corrections. Because of the non-renormalizability of the model we have to
regularize the meson loops with an independent cutoff parameter Lambda_M.
Whereas for moderate values of Lambda_M the pion properties change only
quantitatively we encounter strong instabilities for larger values of Lambda_M.
