I have a multisite installation with Domain Mapping.
Generally this works fine, however it seems to break the Twitter login with the WP Social Login. If I log in via Twitter, it redirects to the admin page. I'm logged in, but not back on the post I came from. I've tried using both http://goodevilgenius.blogs.goodevilgenius.org/ and http://goodevilgenius.org/ as the callback URL.
If I use the plugin with a non-mapped site, Twitter login works fine. Facebook login also works fine (haven't tried others).