Descriptive Problem Summary:
If you have someone banned via your pager, and visit their classified ad, it will say "[key] has banned you from replying."
Obviously you shouldn't be able to to reply, it's just the message that's misleading.
Numbered Steps to Reproduce Problem:
1. Visit a post in classified ads.
2. Block the author's key in your pager.
3. Refresh post.
Perhaps a more appropriate message would be, "Author is banned in your pager." or something of the like.