VBA deleting a duplicate copy of chart object fails in Excel 2013

I have a VBA code that is intended to copy the contents of a range into a chart, to be able to export it to a PNG file (+some post-processing using an external command). Here is the relevant part:

Sub GenererImage()  ' Entry point
    getparams    ' Collect parameters and define global variables
    MiseEnPage.Range(ZoneImage).CopyPicture Appearance:=xlScreen,Format:=xlPicture
    Application.DisplayAlerts = False

    With ObjetGraphique.Duplicate
        .Chart.Paste
        .Chart.Export Filename:=CheminImage, Filtername:="PNG"
        .Select
        .Delete
    End With
    Application.DisplayAlerts = True
End Sub

The getparams procedure called in there is just collecting some parameters from another worksheet to define:

• "MiseEnPage": reference to the worksheet object where the range I want to copy exists,
• "ZoneImage" is set to the "B4:F11" string (refers to the range address),
• "ObjetGraphique" is a reference to a ChartObject inside the "MiseEnPage" sheet. This ChartObject is an empty container (I am mainly using it to easily set the width and height).
• "CheminImage" is a string containing the path to the picture filename on disk.

This code used to work perfectly in Excel 2010. Now my company has deployed Excel 2013 and my code now fails on the .Delete line, leaving the copy of the ChartObject (with the range picture pasted inside it) on the sheet and stopping macro execution.

I have tried activating the worksheet first, selecting the duplicate prior to deleting it and other things, to no avail. When tracing the execution in the debugger it chokes on the delete line with error 1004.

I am frustratingly stuck. Any clue?

If this works

 With ObjetGraphique.Duplicate
    .Chart.Paste
    .Chart.Export Filename:=CheminImage, Filtername:="PNG"
    .Select
End With
Selection.Delete

we have to assume that either the With is holding a reference and preventing the delete, or that the delete routine called by the selection object is not the same delete that's called by ObjetGraphique.Duplicate.delete, or that it's a subtle timing bug and that the extra time it takes to retrieve the selected object is enough to fix it.