Hi
I purchasd a cs600 in April last year 2007 and after a while it had the very same problem as yourself. Failure to transfer the heartrate details to the pc for viewing .
I got in touch with Polar direct and explained the problem to them they were helpful. The unit was returned to them and returned to myself with the same problem . I again got in touch with polar and returned the unit eventually they replaced the unit with a new one under warranty last December but again now it seems to be developing the same problem again . The unit is still under warranty but at least now i know that other people are having the same problem as myself and i will inform polar about this.
Did you get the problem sorted out yourself .

Barney