I have a part with two configurations that I cannot get to activate in the assembly. Both the default and the new configurations show in part mode, but only the default part configuration shows in the assembly tree. If I right click in the feature tree on the part to access the properties only the default configuration shows in the Reference Configuration dialog box. I also tried bring up the part first and changing to the new config and then bringing up assembly to load the part. What else do I need to do?