"Accept all changes" is not the same as "Delete all comments".
You have to click on both commands on the Reviewing toolbar.

whatsupwithword03 wrote:

I am comparing two MS Word documents that have "Accepted All Changes" in each
document. The old document had reviewer comments. The later version had
deleted those comments. After doing a document compare, the later version
fills in nicely with change bars, etc, but it shows the deleted comments as
active comments. They instead should be deleted (I would think). Why do
deleted comments reappear after a document compare? Thanks!