Cheers LOK - as it happens, I need to get one of those as well - basically I'm using a MacBook - and the Polar USB adaptor isn't compatible with Macs! So the workaround is to use a serial Polar IR adaptor, attached to one of those serial to USB adaptors that you use!
Comments
if you can't get one then have you thought about trying to make a USB one work with a USB to serial converter?
i had the same problem with an old pda that would only take serial connection
managed to make it work on my new USB only pc
made by keyspan as i recall
something like this
but you may need different one
http://www.keyspan.com/products/usb/USA19HS/
http://www.expansys.com/p.aspx?i=121827