Currently (2.3.1 on WP3.7.1), Mantra requires manually setting the option POST COMMENTS LINK as either “Show” or “Hide”.
If comments are disabled on a post, then the “Leave Comments” option should not appear, even if the option is set to “Show”.
Request: Either add an “Auto” option to allow the “Leave Comments” visibility to be solely based on the settings of the post, or modify “Show” setting so it respects posts which have comments disabled.
Thanks for the great theme!