Whats that song: "im in love uh uh love uh uh"

theres this song stuck im my head thats annoying. i dont know the girl wh sings it and dont the name of the song. help me out. it goes im in love uh uh love uh uh love uh ah and im in etc. the video is all black and white like a piano and she has a manacan in the video that turns into a guy. u know the song or name of singer.

Sounds like something they would've put out

regina spektor - fidelity..
http://youtube.com/watch?v=SGTDRztaCCw