  We present results for pseudoscalar decay constants of heavy-light mesons
using both quenched and N_f = 2 dynamical fermion configurations. A variety of
fermion actions is investigated : Wilson, nonperturbative clover, and fat-link
clover. For heavy quarks the Fermilab formalism is applied. In the quenched
approximation, results with the nonperturbatively improved clover action of the
Alpha collaboration allow us to study the systematic error of the continuum
extrapolation from the Wilson action. In addition, we use quenched
configurations to explore the effects of fattening. The lessons from the
quenched analyses are then applied to data with dynamical fermions, where both
Wilson and fat-link clover actions have been used. This allows us to attempt a
continuum extrapolation of the dynamical results.
