  Low Surface Brightness (LSB) galaxies are dominated by dark matter, and their
rotation curves thus reflect their dark matter distribution. Recent
high-resolution rotation curves suggest that their dark matter mass-density
distributions are dominated by a constant-density core. This seems inconsistent
with the predictions of Cold Dark Matter (CDM) models which produce halos with
compact density cusps and steep mass-density profiles. However, the
observationally determined mass profiles may be affected by non-circular
motions, asymmetries and offsets between optical and dynamical centres, all of
which tend to lower the observed slopes. Here we determine the impact of each
of these effects on a variety of halo models, and compare the results with
observed mass-density profiles. Our simulations suggest that no single
systematic effect can reconcile the data with the cuspy CDM halos. The data are
best described by a model with a soft core with an inner power-law mass-density
slope alpha = -0.2 +/- 0.2. However, no single universal halo profile provides
a completely adequate description of the data.
