After today's Word security update KB2910916 I cannot open some word documents from a vb.net application, although Word itself will open them (with appropriate file block settings). Error is that file block settings prevent opening, but this is not seen when opening the same document directly from Word.

It appears this update overrides the trust centre settings for some files created in Word 97, though not all appear to be affected, and only a programmatic opening of the document is affected using WordApp.documents.open(filename).