Man, they get an F in communications. I had the same issue, didn't get it to work until I tried the fix listed here. Thank you, thank you! My other issue is the battery that came with the speed sensor was dead.

The first paragraph in the instructions should say the three icons in the top left indicate the presence of a speed, cadence, and heart monitor. YOu have to read the instructions with a magnifying glass to find that. The device seems to be good, the instructions not so good.

I see this works with a heart sensor. Anyone tried that yet?