Just recently purchased the AVR stick. The firmware appears to be broken (?). I have tried plugging it into two different computers and neither computer fully enumerates the device. Windows reports it as an unrecognised USB device. Which is not helpful.
USBView (http://www.ftdichip.com/Resources/Utilities/usbview.zip, best piece of software Microsoft ever wrote) reports the following for the device:
bMaxPacketSize0: 0x00 (0)
Current Config Value: 0x00
Device Bus Speed: Low
Device Address: 0x00
Open Pipes: 0
This is admittedly not much to go on.
Also the stick does flash the white then the orange/yellow led once each when initially plugged in.