Serial to USB Adapter Not Recognized

I have a new Garmin Personal Trainer which has Mac software to keep track of your training data. However, the unit only comes with a serial cable, so I have purchased a serial to USB cable. The unit is not recognized by my IMac, what am I missing? The mini CD will not work in the Imac and besides the instructions says it is a PC driver disc.

Does that adapter have a brand name and Model #?

This is generic USB to Serial Converter made in Taiwan - says it supports PC and MAC

Make sure its recognized, open up system profiler and look if the device is listed under the USB section.

I use a Keyspan USA-19HS one, it has Mac drivers and it works perfectly.

Now if there only was a modern terminal app that still had serial support. I HATE the way Zterm works... but at least it works.