I have a WordPress Multisite with a main domain and subdomains. I installed buddypress to test it on one of my subdomains at profiles.fatfreefilm.com
Now my main domain defaults to the buddypress subdomain page when you type the URL into a browser and don't include the "www"
So to be clear, now when I type in http://fatfreefilm.com it redirects to http://profiles.fatfreefilm.com/