I just installed Rockbox on my Gigabeat F40 and the cradle doesn't work -- the Win2K machine I'd built to support Gigabeat Room doesn't see a thing when the Gigabeat is inserted. Same is true for my work Win2K laptop.
It DOES recognize the Gigabeat via the USB cable direct, though (whew!)

I get the same result with my Linux machine (Kubuntu 6.10).

The work laptop freezes and dies -- but that's probably due to the USB PCMCIA card I have to use ever since the USB ports blew out a year ago. (Rigid corporate policies stink.

)