Yes, I've checked your site. And could say that all are normal. You set comments per page to 10, but you also set maximum pages to 15... In this case as described in parameter description
This option will cause limited pagination. Using it you can increase the number of "Comments per page" parameter to avoid this limit. The default is 15;
So if you set maximum number of pages it will never exceeded - and instead adding 16th page JComments will dynamically increase Comments per page. This allows to prevent unrestricted growing of pages and page layout broke.
Sorry if this parameter description not understandable. My English isn't so good so if you could suggest more correct parameter description I'll update it.