The Madge fans running in here.
She's not suing over the beat, she's suing because of the lyrics. Her song is called "Juda" and Gaga's lyrics are "Juda, Juda ah ah".
As for the "Invading My Mind" thing, it's a different lawsuit, or a different case or something. But Gaga wrote that song when she was a ghost writer, I believe. It was originally for another artist.