Exact same problem with mine. I went back to the Ant agent and downloaded a firmware update to 2.9- it took a long time but eventually finished. I thought that might solve the problem with the new Express but nope- same as your problems. It won't connect to the device.
I cannot even get the Express software to load. I just get a "Installation Failed" message. It sounds like I would be wise to wait until all the bugs are sorted!