WPMU MultiDomains and Domain Mapping

I'm trying to setup a buddypress site on Wordpress 3.1 that will allow users to register and map as many domains as they'd like to their blogs. I've setup a subdomain multisite and have the domain mapping plugin enabled but I can't get multidomain enabled. When network activating multidomain I get "The plugin does not have a valid header."

Am I going about this the right way? Any help would be appreciated.