We consider the Isgur-Wise function xi(omega) within a new modified version
of a heavy-light chiral quark model. While early versions of such models gave
too small absolute value of the slope, namely xi'(1) of about -0.4 to -0.3, we
show how extended version(s) may lead to values around -1, in better agreement
with recent measurements. This is obtained by introducing a new mass parameter
in the heavy quark propagator. We also shortly comment on the consequences for
the decay modes B --> D D-bar.Comment: 20 pages, 7 PS figure, LaTe
