My User Reports plugin is showing posts but not comments

My User Reports plugin is showing WordPress posts on my WordPress multisite, but it's not showing WordPress comments. (On a hunch I added comments as a new line in the Post Indexer plugin, but I bet comments isn't a post type. Anyway, it hasn't produced any comments in the reports.) The search perameters should have brought up the users listed.

My site is YouRead.Us.

Thanks for your help.