It was driving me nuts with not picking up the signal - once I even put it in the washer at gentle cycle to get gunk out of the textile wearlink strap.

That didn't help and I haven't worn it in the past 3 months or so, getting passive-agressive at Polar...

Saturday before the race I got desperate (BF had taken his out of the country) so I remembered Kelownagirl mentioning scrubbing the contacts.

Took my toothbrush and really got into those buttons. Lo and behold there WAS gunk in them and lo'er and even more beholder - it worked again.