The non-Gaussian fluctuations of conserved quantities, like net baryon
number, were proposed recently as a tool for search of the critical endpoint
of strongly interacting matter. However, studies of the energy dependence
of higher-order cumulants of net-protons in A+A collisiins at
RHIC and SPS have not revealed any convincing evidence of criticality.
We argue that in the current analysis the non-dynamical contribution of
trivial volume fluctuations are large, and we propose to use the reduced
cumulants with the volume of interaction defined for each event