exploding plines routine

Hi friends,
This is my first attempt to write a vba code.
My aim was to select all polylines among all selection
and explode them.That worked fine!.But all the lines i
obtained were duplicates.Can anyone help me with this
problem? I would be very thankful.
Here goes the code..............
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Sub exp()
Dim Mypline As AcadLWPolyline
Dim fType(0) As Integer, fData(0)
Set adSS = ThisDrawing.SelectionSets.Add("adSS")
If Err Then Set adSS = ThisDrawing.SelectionSets.Add("adSS")
adSS.Clear
fType(0) = 0: fData(0) = "LWPOLYLINE"
adSS.Select acSelectionSetAll, , , fType, fData
For Each Mypline In adSS
Mypline.Explode
Next Mypline
ThisDrawing.Application.Update
adSS.Clear
End Sub
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