Assembly driven part configurations - driven dimensions in DT's

I thought I had this problem solved, but not so.  I would like to use the 'top down' design technique in our design flow.

I'm trying to get an assembly to update a part's design table.  I have two configurations of my assembly, and two configurations of my part (both with DT's).  I would like to be able to change the values in the assembly's DT, and have the part's DT update.  If I activate each config in my assy, my part configs are updating, but the driven dimension in the part's DT is not updating.  What am I doing wrong?

I've attached a couple of files to illistrate what I'm attempting.

SolidworksConfigurations design Tables