  We study nonperturbative corrections to the inclusive rare decay B -> X_s l^+
l^- by performing an operator product expansion (OPE) to O(1/m_b^3). The values
of the matrix elements entering at this order are unknown and introduce
uncertainties into physical quantities. We study uncertainties introduced into
the partially integrated rate, moments of the hadronic spectrum, as well as the
forward-backward asymmetry. We find that for large dilepton invariant mass q^2
> M_{\psi'}^2 these uncertainties are large. We also assess the possibility of
extracting the HQET parameters \lambda_1 and \bar{\Lambda} using data from this
process.
