why "device unsupported" for every USB device using RCN's natty?

In trying out RCN's Natty alpha3 image:

pretty much every USB device I try gets a report from the usb driver:
USB <version>: device v<vid> p<pid> is not supported

This seems to happen on every enumeration event. But the device finds its driver,
and modulo driver bugs, seems to work. What is up with that?