  Adding to the long standing "rho-pi puzzle" in psi(3686) and J/psi decays,
recently BES reported the branching ratio of psi(3686) -> Kshort Klong which is
enhanced relative to the pQCD " 12% rule" expectation from the branching ratio
of J/psi -> Kshort Klong. If the enhancement is due to the mixing of the S- and
D-wave charmonium states as in the rho-pi case, the newly measured branching
ratio of psi(3686) -> Kshort Klong gives a constraint on the psi(3770) ->
Kshort Klong. It serves as a good test for the scenario of the S- and D-wave
mixing in the psi(3686) and psi(3770).
