So far there where a few issues with the Runge-Kutta-Nyström solvers concerning their accuracy:
All Nyström solvers used, in these issues, are designed for 2nd order ODEs which are not dependent on the first derivative.
However most of the issues feature this type of 2nd order ODE. The lack of accuracy may just boil down to the solvers not being designed for theses types of problems. Any ideas on how to prevent these issues in the future?