The text on my sheet of labels mysteriously moves after I run some code.

I create a sheet of labels--in my test, I've used Avery 5066 file folder labels. I run the code listed below. The MsgBox says that my insertion point is at 58.5 points. I run the code a second time. The MsgBox says that my insertion point is at 60.75 points. But the code shouldn't be doing anything to the document????!!!!!???

Any thoughts on what's causing this shift? (If you alter the PageSetup to reduce the distance that the header appears from the edge of the page, the insertion point is returned to 58.5 points.--but why would this matter?)

Public Sub TextPositionMoves()
Dim oFooter As HeaderFooter
Dim oField As Field
MsgBox "Insertion Point is at: " & Selection.Information(wdVerticalPositionRelativeTo Page)
For Each oFooter In ActiveDocument.Sections(1).Footers
For Each oField In oFooter.Range.Fields
End Sub