XML dialog box

I have an application that uses Word from Access. The Word documents are
encrypted and passworded and in Word 2002. When the MS Word associated with
the application is 2007, every time I save such a document in Word, I get a
question about whether to move to the new XML .docx format because it is
better protection for the encrypted/passworded file. I don't want to convert
to the new format at the moment. This is getting a pain.
Is there a way to stop this pesky question coming up every time I save a
Word document?
Many thanks