  The contribution of the hadronic continuum in the QCD sum rule calculation of
the parameters entering in pseudoscalar meson mixing is evaluated by making use
of simple integration kernels tailored in order to practically eliminate the
contribution of the hadronic continuum. This approach avoids the arbitrariness
and instability inherent to previous sum rule calculations. An independent
evaluation of the mixed quark gluon condensate $\left\langle QGC\right\rangle
=$$\left\langle
g\bar{q}\sigma_{\mu\nu}\frac{\lambda^{a}}{2}G_{\mu\nu}^{a}q\right\rangle $
which enters in the calculation is presented as well as the calculation of the
K-meson decay constant $f_{K}$ to five loops.
