How to correctly extract the chi2, ndf, p-value of a RooFitResult

Hi everybody,
is it possible to still answer this question? Basically, my question was: “What is the correct way to extract a chi², ndf and p-value of of a RooFitResult?”. Of secondary importance is: “Why do all my tried methods lead to different results?”. I am sorry if I provided too much or little detail or asked my question in the wrong way. Also I am using Root v6.24/02 and if necessary I could come up with a minimal working example.
Best,
Alex