  A Hoelder inequality analysis of the QCD Laplace sum-rule which probes the
non-strange (n\bar n) components of the I={0,1} (light-quark) scalar mesons
supports the methodological consistency of an effective continuum contribution
from instanton effects. This revised formulation enhances the magnitude of the
instanton contributions which split the degeneracy between the I=0 and I=1
channels. Despite this enhanced isospin splitting effect, analysis of the
Laplace and finite-energy sum-rules seems to preclude identification of
a_0(980) and a light broad sigma-resonance state as the lightest isovector and
isoscalar spin-zero $n\bar n$ mesons. This apparent decoupling of sigma [\equiv
f_0(400-1200)] and a_0(980) from the quark n\bar n scalar currents suggests
either a non-q \bar q or a dominantly s\bar s interpretation of these
resonances, and further suggests the possible identification of the f_0(980)
and a_0(1450) as the lightest I={0,1} scalar mesons containing a substantial
n\bar n component.
