  The non-equilibrium fluctuations of power flux in a fluidized granular media
have been recently measured in an experiment [Phys. Rev. Lett. 92, 164301,
2004], which was announced to be a verification of the Fluctuation Relation
(FR) by Gallavotti and Cohen. An effective temperature was also identified and
proposed to be a useful probe for such non equilibrium systems. We explain
these results in terms of a two temperature Poisson process. Within this model,
supported by independent Molecular Dynamics simulations, power flux
fluctuations do not satisfy the FR and the nature of the effective temperature
is clarified. In the pursue of a hypothetical global quantity fulfilling the
FR, this points to the need of considering other candidates than the power
flux.
