  We report on angle-resolved magnetization measurements on
NdFeAsO$_{0.65}$F$_{0.35}$ (Nd-1111) single crystals. The field dependence of
the critical current density, $J_c$, is non-monotonous in these crystals at all
orientations and temperatures due to the fishtail effect, which strongly
influences the angular dependence of $J_c$. The currents decrease as the field
is tilted from the crystallographic c-axis at low fields, but increase at high
fields. A peak occurs in the angular dependence of $J_c$ at intermediate
fields. The critical currents are significantly enhanced after irradiation with
fast neutrons and the fishtail disappears. The different current anisotropies
at low and high fields, however, persist. We discuss the data in the framework
of the anisotropic scaling approach and propose a transition from dominant
pinning by large defects of low density at low fields to pinning by small
defects of high density at high fields in the pristine crystal. Strong pinning
dominates at all fields after the irradiation, and the angular dependence of
$J_c$ can be described by anisotropic scaling only after an appropriate
extension to this pinning regime.
