  A new construction is presented of scalar-flat Kaehler metrics on non-minimal
ruled surfaces. The method is based on the resolution of singularities of
orbifold ruled surfaces which are closely related to rank-2 parabolically
stable holomorphic bundles. This rather general construction is shown also to
give new examples of low genus: in particular, it is shown that CP^2 blown up
at 10 suitably chosen points, admits a scalar-flat Kaehler metric; this answers
a question raised by Claude LeBrun in 1986 in connection with the
classification of compact self-dual 4-manifolds.
