Disabling drag and drop - paste problems

I have disabled drag and drop in a spreadsheet as shown below, but this also
prevents pasting data into the workbook that has been copied from another
workbook - how can I overcome this? (Data copied from another application -
eg Word - can be pasted fine, except it sets the 'locked' property for the
cell, even though the worksheet is protected)

We are using Excel 2000, but the problem also exists in Excel 2003

Any help gratefully received!

Private Sub Workbook_Activate()
Application.CellDragAndDrop = False
End Sub