  With the success of dynamical mean field theories, solvers for
quantum-impurity problems have become an important tool for the numerical study
of strongly correlated systems. Continuous-time Quantum Monte Carlo sampling of
the expansion in powers of the hybridization between the ``impurity'' and the
bath provides a powerful solver when interactions are strong. Here we show that
the usual updates that add or remove a pair of creation-annihilation operators
are rigorously not ergodic for several classes of broken-symmetries that
involve spatial components. We show that updates with larger numbers of
simultaneous updates of pairs of creation-annihilation operators remedy this
problem. As an example, we apply the four operator updates that are necessary
for ergodicity to the case of d-wave superconductivity in plaquette dynamical
mean-field theory for the one-band Hubbard model. While the results are
qualitatively similar to those previously published, they are quantitatively
better that previous ones, being closer to those obtained by other approaches.
