I am using Multisites with Headway Themes V:3.5.5 and Buddypress V:1.7.2.
When I activate Events Manager the positioning of the Buddypress members section is pushed to the right, over riding the CSS. I did a test on several installs and the same thing happened.
I un-installed and did a complete removal of all data but could not get rid of the issues that the activation of Event Manager caused.
The site is ila.workmate.info, you will not be able to access/join because of the nature of the site, PM me if you are from Events Manager and need access.
I have spoken to Clay from Headway about this