First prepare 2 documents for upload. Let's say 2 MSWord documents, A.doc and B.doc.
1) Create a new page, enter some text
2) Upload A.doc
3) Remove A.doc
4) Upload B.doc
5) Activate the version where you uploaded A.doc (should be version 2.1)
6) Delete the latest version of the page (this *should* take you back to version 4.1 where you uploaded B.doc)
Examine the attachments page:
It will show A.doc and B.doc (which in my opinion is strange, because I would expect to only find B.doc).
Try to open A.doc (this is possible), now try to open B.doc (this is NOT possible).