Aha, I did get it to work. Here are the steps I used:
1. Unplug and replug the USB transmitter/receiver.
2. Start the Triax software.
3. Click the Sync button.
4. Click OK when prompted to put the watch into PC mode.
5. Put the watch into PC mode and set it next to the transmitter/receiver.
Everything transferred OK.
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Oh, I am also using 10.4.1.