OLE won't remove text

I’ve got a big chunk of LotusScript in a Notes client application which detaches a copy of a Word file to the user’s machine, opens it, and uses OLE to enter text at various bookmarks or remove words and/or paragraphs based on various options the user has selected in a Notes document. This has all worked very well except, recently, for one or two people. Their problem is that it mostly works (the file is properly written to the hard drive, it opens, and text is inserted as appropriate), but nothing I do will remove existing text. Frex, this is supposed to go to a bookmarked batch of text and remove it:

Call worddoc.ActiveWindow.Selection.GoTo(, , , “the_section”)

Call worddoc.activewindow.Selection.TypeBackspace

Works for most people, but not for our two problematic people. Form fields have the same problem:

Call worddoc.FormFields(“special_field”).Select

Call worddoc.ActiveWindow.Selection.TypeText(“Hi!”)

For most people, this replaces the contents of the form field, but for the people experiencing the problem, it appends “Hi!” to the placeholder text already there.

So far as I can tell, the people are on the same overall versions of Word and Notes that everybody else has (Notes 6.0.3 and Word 2003; that’s certainly what I’ve got), and I believe we’re all on the same version of XP, though it’s certainly possible that we’re on different point releases or have different batches of service packs.

So, then, has anybody else seen this problem or one much like it? Since I’m not sure what to look for at this point, can anyone even suggest questions I should be asking?