Video recording problem...?

I have a new Flip Video recorder, and I wanted to video myself playing the flute on it. One problem:

Whenever I try, even if I play softly, it echoes too much, and it sounds like either an out-of-tune french horn or a baby elephant who knows how to hum.

I've tried three rooms, all of which absorbed different amounts of sound, but nothing works. I was looking forward to an introduction of myself by playing a song with a stuffed wolf in the background.
If anyone knows how to solve the problem, whether on the recorder, in the room or on iMovie, I would be grateful for help.