Device.Net: Mac: USB hot plug notifications don't seem to work.

I’m running the Device.Net.LibUsbSample console app on a mac, and the initial enumeration seems to find my USB device:

Currently connected devices: 
usbdev20.30

Console sample. This sample demonstrates either writing to the first found connected device, or listening for a device and then writing to it. If you listen for the device, you will be able to connect and disconnect multiple times. This represents how users may actually use the device.

1. Write To Connected Device
2. Listen For Device

But if I choose option 2 and unplug and then re-plug the device, i never get a notification. I also tried it unplugged to start and then chose 2, and then plugged in, and still no notification.