Tapered Panels, Properties Ruined When Copied or Moved

[LiveMike]

When I move or copy  variable thickness (tapered) panels but stay in the same plane, all is well.  

Otherwise, the properties are ruined.  The panel thickness becomes large.  

Is there a way to prevent this problem?

I suspect it related to the definition of the panel thickness.  The coordinates versus thickness relationship is not updated with move/ copy.

[Rafal.Gaweda]

 The coordinates versus thickness relationship is not updated with move/ copy.

Exactly.