Problem with Garmin Communicator plugin

Just saw you had added support for downloading data directly from Garmin devices :-)
I wanted to try it out right away, but the page where I'm supposed to upload gives me the message "The plug-in was not unlocked successfully".

The plugin has been installed from the Garmin site, and the test-page correctly finds my device (plugin v2.9.1.0). I have tried rebooting, and have attempted with both Firefox 3.0 and IE 8.0 (Win XP).
Has anyone had any similar issues? Suggestions on troubleshooting?

Btw.: What would make this feature even more useful would be an equivilant to the Ant Agent that comes with the Garmin devices. This way it would require zero effort to keep the training log up to date with cardio activities. But I know that developing for particular OSs is a pain compared to web-apps...