WFBrian on "[Plugin: Wordfence Security] Login attempts not reported?"

There may be a conflict going on. If you disable Jetpack, does Wordfence function as expected? This post addresses the conflict issue:

https://wordpress.org/support/topic/wordfence-and-jetpack-protect?replies=7

Also, you may need to increase the memory on your site.

http://docs.wordfence.com/en/Wordfence_system_requirements#Memory