  There is a recent claim by Guralnik and Manohar \cite{GM} to have established
a rigorous lower bound on $\bar \Lambda$, the asymptotic difference between the
mass of a heavy flavour {\em hadron} and that of the heavy flavour {\em quark}.
We point out the flaw in their reasoning and discuss the underlying physical
problem. An explicit counterexample to the GM bound is given; one can therefore
not count on a refined proof to re-establish this bound. *********** Uses LaTeX
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