I recently found a pr 4 .edu site that is unmoderated and the comment links are ********.
The system is set up so that the newest comments show up at the top of the page which is pr 4 but as more comments are added they are moved down and eventually rollover to the next page which is pr 0.

My sites are showing the pr 4 backlinks at the moment. I am wondering if once more comments are added and these links roll over to the pr 0 page will they be recategorized as pr 0 links or will I keep the pr 4 juice I am getting now?

As the links move down, you will get less juice.

There are 2 types of comment pages - new comments at top, and new comments at bottom. In a way, I prefer the latter, because often you can stick a reply high up and it will stay.

yes you will get less juice once the comment moves down

Finally figured out how to do that, reply to the comment block that is furthest over...
Cool