I have node page created with Panels.
Comments are added to the panel as "Node comments" item.
I set there "30" comments per page. But in my content type settings there is set 50 comments per page.
When I try to visit comment by permalink (e.g. www.example.com/comment/199) I can't see the comment because I'm on wrong "page" of pager.
So when I'm on the "comment/%" page Drupal calculates $page number using content type settings because he doesn't know about Panel settings. And Drupal thinks that there are 50 comments per page.