  We report experimental and numerical evidences that the dynamics of the
director of a liquid crystal driven by an electric field close to the critical
point of the Fr\'eedericksz Transition(FT) is not described by a
Landau-Ginzburg (LG) equation as it is usually done in literature. The reasons
are related to the very crude approximations done to obtain this equation, to
the finite value of the anchoring energy and to small asymmetries on boundary
conditions. We also discuss the difference between the use of LG equation for
the statics and the dynamics. These results are useful in all cases where FT is
used as an example for other orientational transitions.
