Problem plotting slices of RooSimultaneous

Hi,

I am doing a simultaneous fit of several different 1D distributions using RooFit. The fit itself works fine, but when I try to plot slices of the result, the data is plotted correctly, but only the PDFs corresponding to the last category are plotted, no matter which slice is selected.

I've attached a script that recreates this behavior, along with its text and .ps output.

---Sean Dobbs