  Recently \REF\dk{Simon Dalley and Igor Klebanov,'Light Cone Quantization of
the $c=2$ Matrix Model', PUPT-1333, hepth@xxx/920705} \refend Dalley and
Klebanov proposed a light-cone quantized study of the $c=2$ matrix model, but
which ignores $k^{+}=0$ contributions. Since the non-critical string limit of
the matrix model involves taking the parameters $\lambda$ and $\mu$ of the
matrix model to a critical point, zero modes of the field might be important in
this study. The constrained light-cone quantization (CLCQ) approach of Heinzl,
Krusche and Werner is applied . It is found that there is coupling between the
zero mode sector and the rest of the theory, hence CLCQ should be implemented.
