An add-in I've created worked fine in PowerPoint 2003, but gave an error in
PowerPoint 2007, B2TR.  The cause appears to be that Find does not return
NOTHING if the search string is not found.  Here's the example from Help:
  Set txtRng = shp.TextFrame.TextRange
  Set foundText = txtRng.Find(FindWhat:="CompanyX")
  Do While Not (foundText Is Nothing)
      With foundText
          .Font.Bold = True
          Set foundText = _
              txtRng.Find(FindWhat:="CompanyX", _
              After:=.Start + .Length - 1)
      End With
  Loop

I got my code to work by replacing
  Do While Not (foundText Is Nothing)
with
  Do While Not (foundText = "")
Looks like this is a bug in VBA:  when the search text is not found, the
variable is set to "", rather than NOTHING.

Chris