I'm going nuts with my wearlink (the textile variety) polar. I hate it. It keeps telling me I'm dead. I had the batteries replaced last July, I believe they even gave me new straps. Paid good money for the rehaul.
The old, plastic one, you just have to get it a wee bit wet and it reads.

I haven't gotten round to calling them to complain, but I am seriously considering ditching it and getting some other brand.