Weird bug on powerpoint vba

Question

I have a "mynote" textbox on a slide. If I execute:

Sub test()

            If ActiveWindow.Selection.SlideRange.Shapes("mynote").Visible Then
                MsgBox "ok"
            End If
end sub

It works.

But If I attach a shape with this macro:

Sub test(oShape As Shape)

            If ActiveWindow.Selection.SlideRange.Shapes("mynote").Visible Then
                MsgBox "ok"
            End If
end sub

It doesn't work (no error message, no "ok" message)