  We have performed a QCD next-to-leading order (NLO) calculation for Deep
Inelastic Scattering (DIS) retaining the full parton and hadron mass
dependencies. We find that the gluon initiated contributions to DIS processes,
such as charm production, are {\it comparable} in magnitude ({\it i.e.}, $30\%$
to $100\%$) to the ``leading-order'' (LO) sea-quark processes. The
``slow-rescaling" prescription and the full NLO formalism are compared in a
quantitative manner. The use of DIS distributions and the inclusion of the
charm mass via slow-rescaling are not sufficient to mimic the correct NLO
physics. These results imply that previous analyses of charm production data to
extract the strange and charm content of the nucleon, as well as the precise
determination of Standard Model parameters based on these analyses (such as the
Weinberg angle), need to be reassessed.
