  The Kreiss-Majda Lopatinski determinant encodes a uniform stability property
of shock wave solutions to hyperbolic systems of conservation laws in several
space variables. This note deals with the Lopatinski determinant for shock
waves of sufficiently small amplitude. The determinant is known to be non-zero
for so-called extreme shock waves, i. e., shock waves which are asscoiated with
either the slowest or the fastest mode the system displays for a given
direction of propagation, if the mode is Metivier convex. The result of the
note is that for arbitrarily small non-extreme shock waves associated with a
Metivier convex mode, the Lopatsinki determinant may vanish.
