  The canonical description is presented for the string with pointlike masses
at the ends in 1+1 dimensions in two different gauges: in the proper time gauge
and in the light cone one. The classical canonical transformation is written
out explicitly, which relates physical variables in both gauges, and
equivalence of two classical theories is demonstrated in such a way. Both
theories are quantized, and it is shown that quantum theories are not unitary
equivalent. It happens due to the fact that the canonical transformation
depends on interaction. The quantum Poincare algebra proves to be closed in
both cases, so that the requirement of Poincare covariance is not able to
distinguish between two versions of the theory.
