[quote user="Darin Rodberg"]The textnode has 1 TextLine[/quote]
I tried your code on a standalone text node, and it works OK. I think the problem may be that the node is inside a cell. You may need to do something like this...
Do While oCell.MoveToNextElement(True)
Dim oComponent As Element
Set oComponent = oCell.CopyCurrentElement
If oComponent.IsTextNodeElement Then
Dim oNode As TextNodeElement
' Make a copy of the TextNodeElement
Set oNode = oComponent.AsTextNodeElement.Clone
Debug.Print "Replace text node line 1 with '" & txt & "'"
oNode.textLine(1) = txt ' Global variable
oCell.ReplaceCurrentElement oNode
End If
Loop