Unable yo Set Position,PivotItem Class help!!

[E_DPSG]

I am getting a debug error with setting the position within a pivot.

Here is my code:

VisibleItems=0
For Each PvtField in PvtTabe.RowFields
   if pvtField.Name = "MyName" then
          for  each pvtItem in pvtField.PivotItems
              if pvtItem.Visible=true then VisibleItems=VisibleItems+1
          next
   end if
next

if ActiveSheet.PivotTables("MyPivotTable").PivotFields("MyName").PivotItems("MyItem").visible Then
ActiveSheet.PivotTables("MyPivotTable").PivotFields("MyName").PivotItems("MyItem").position = VisibleItems
End IF

I get the count of items correctly, and it does enter the if clause for visibility, but will not assign the position.

Any Ideas?