I have a Garmin 810 and Edge 1000. The latest version of Express works fine with the 810. But, it will not find the 1000. The MAC finds it and shows the device and microSD card in FINDER but Express just keeps looking. Garmin Webupdater finds the device as well. What is wrong with EXPRESS???????? I can't configure wifi.
Having a similar issue with my Nuvi. Did you find a resolution?
Update: I solved my problem by re-registering my Nuvi. The latest version of Express didn't like the stored profile. I re-registered by clicking on "Add a device" and it works now.