A family of Microsoft word processing software products for creating web, email, and print documents.
I agree with Rich on this... The probable cause of Word "not even seeing" what's on the Clipboard is that there is nothing on the Clipboard - at least nothing in a form Word can recognize. Have you examined the Clipboard content to verify what, if anything, it contains?
Your subject states that "Word won't paste text from other sources" but in your message you conclude by stating that you "...can cut/paste text from other sources into word... with no problem". Depending on which statement is accurate, I'd say the problem most likely lies with the Scrivener product or its interaction with OS X.