If it makes you feel any better, the # on mine is NEVER right, even if I find my own HB. The cheaper, the less likely they are super accurate. I always just get my cell phone timer and count the heartbeats out for 15 seconds and multiply by 4.
TFS the video Heather, pretty cool!
My numbers on the doppler are never right. Like Heather said, I just like to be able to hear it and know it's fast and that's reassuring for me. Also, I've heard the galloping horses sound a few times, but for the most part when I find the baby, I hear a ...erm...heartbeat for lack of better words. I don't think I'm right on it when I hear that... I've noticed when it's that galloping sound it's also very loud, but if I move it a little bit, it gets softer and more heartbeat like. It's the same beat though - so I know it's still baby.