Chart formatting .top error

I created a sheet in XL 2003 and was recently upgraded to 2007 and some of my scripts are failing.

I have charts that the users can zoom in on to get a better look.
The debug points to the .Top = 0

So I assume all the formatting is wrong

Here is the script example.
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Sub CHARTACD()
ActiveSheet.ChartObjects("Chart 16").Activate
    ActiveChart.ShowWindow = True
    With ActiveWindow
        .Top = 0
        .Left = 0
        .Width = 750
        .Height = 500
    End With
    End Sub

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Any help would be appreciated.