Charts can not be shown after updated by vba

[kelly]

Hi,
I wrote some syntax to update data(Excel) for some slides in
powerpoint.
The problem is some charts are blank when opening the updated file,
but the bars will be shown after doule click the charts.
How come??? and how to solve them??

Here is the syntax:
......................................................
For Each oPPTslide In oppPrs.Slides
For Each oPPTShape In oPPTslide.Shapes
If oPPTShape.Type = msoEmbeddedOLEObject Then
If oPPTShape.OLEFormat.ProgId = "MSGraph.Chart.8" Then
Set oExlrange =
Application.Worksheets(i).Range("A1").CurrentRegion
oExlrange.Copy
Call Sample(oExlrange)
Worksheets("Sample Size
Definition").Cells(oPPTslide.SlideIndex, 3) = SampleC
Set oGraph = oPPTShape.OLEFormat.Object
oGraph.Application.DataSheet.Cells.Clear
oGraph.Application.DataSheet.Cells(1, 1).Paste
i = i + 1
oGraph.Application.Update
End If
ElseIf oPPTShape.Tags("TABLE") = "TABLE" Then
With oPPTShape.Table
For irow = 1 To .Rows.Count
................................................
End If
Next oPPTShape
Next oPPTslide

.....................................
Thanks