In this paper we discuss new variants of the acceleration
technique known as Iterated Defect Correction (IDeC) for the
numerical solution of boundary value problems in ordinary
differential equations. A first approximation, computed by the
backward Euler scheme, is iteratively improved to obtain a high
order solution. Typically, the maximal attainable accuracy is
limited by the smoothness of the exact solution and by technical
details of the procedure. We propose a new version of the IDeC
algorithm with maximal achievable order higher than in the
classical setting. Moreover, our procedure can be shown to be
convergent on arbitrary grids, while the classical IDeC iteration
requires piecewise equidistant grids. Finally, the performance of
this new algorithm for singular boundary value problems is
discussed.