Assembly mass properties not matching document settings

Hi,

I have an assembly that outputs my mass properties in metric (mm and grams), even though the document settings are in imperial (IPS).  I have changed it to "use document settings" every time I open it, but it changes back to "use custom settings" every time I reopen it.  Every other assembly I open shows the correct readout in pounds, but this one won't.  Any ideas?

SolidworksAssemblies