wireless bike computer and cantilever brakes
 

I just got the new polar wireless HRM/bike computer and I can't get it to pick up the sensor. I've moved the sensor around a lot and have the computer mounted on the stem.

My junior sleuthing abilities lead me to believe that the braze ons and brakes on my fork are the sourse of the problem. Is this a rational guess?

Similar problems? Suggestions? I'm about to try and move the computer to the bars and see if that works.