>If I understand you correctly,
>As per the doc, memberwiseClone only copies value types. As to objects (like dataset) it only copies the reference, meaning both references point to the same dataset
>
>Maybe you want DataSet.Copy() http://msdn.microsoft.com/en-us/library/system.data.dataset.copy(v=vs.110).aspx

Thanks, this works.

This is pretty much what I have to do:

            ' If the transmit does not work, we will have a message to show and a list to refresh
            ' As the data changes in the ExportToExcel(), we need to keep a copy
            loDataSet = oData.oDataSet.Copy

            ' Export to Excel
            If Not ExportToExcel() Then
                oProcess.AddJavascriptMessage(cMessage)
            End If

            ' Assign it back
            oData.oDataSet = loDataSet

It would be interesting to find a way to implement that directly in the Data class however. As you said, presently, this behavior copies the value types only. I wonder if there could be a way to add the support of this DataSet.Copy at that level instead of doing it in here, in a client class. By that, I would then be able to use only one command, thus the Clone call, such as mentioned in the first message.