I just reviewed [this suggested edit](http://superuser.com/review/suggested-edits/491971), and while doing so, I noticed that the *Improve Edit* and *Reject and Edit* buttons were absent; only *Approve* and *Reject* were there. I haven't been suspended from editing - the *edit* link still appears under all posts, and I've never done anything bad as far as I know. The edited post wasn't a tag wiki, and I don't have permission to approve edits there anyway.

What happened there? Under what circumstances do those two buttons not appear?