I'm wondering if anyone here has managed to update the firmware on a ForeRunner 405? It's paired and data downloads fine, but I can't get WebUpdater to see it. The Garmin ANT agent is running when I try. This is on OS 10.6, but I've also tried WinXP on a VM with the same result (the ANT agent connects and copies data off of it fine, but WebUpdater doesn't find any device). My FR 405 has 2.10/2.10 on it, and I see from Garmin's site that there is a 2.50 available since June, but their instructions on how to update are useless. They basically just say "run WebUpdater and make sure your device is connected".

You may have better luck posting a question over here:

https://forums.garmin.com/

or you may find your answer browsing through some of the other posts.

Good luck!