Problem with z parameter model.plot_posteriors() while concatenating models

[bramblephoenix]

Probably an old issue by now, but i tried running in parallel using ipython and then concatenating using kabuki. All parameters are concatenated properly except z. I tried both returning directly from the cluster and also by manually saving the models from the cluster and then loading them again and concatenating. For both cases, z does not concatenate and simply ends up showing the plot for the 0th model.