  Quantum transition amplitudes are formulated for a model system with local
internal time, using path integrals. The amplitudes are shown to be more
regular near a turning point of internal time than could be expected based on
existing canonical treatments. In particular, a successful transition through a
turning point is provided in the model system, together with a new definition
of such a transition in general terms. Some of the results rely on a fruitful
relation between the problem of time and general Gribov problems.
