I have some electronics laying around, and decided to see what worked and what didn't. This is tested on my CS40 running F/W 1.0.1A and your mileage may vary.
Cherry keyboard with integrated trackball - Works
Externally powered USB 2.0 hub (Staples branding) - Works - tried with HP optical mouse and USB stick plugged in
USB 3.0 port powered hub (Generic Best Buy brand) - Does not work
I haven't found a list of devices that are specifically tested to work or not work, so this might be a good place to put a list of known go and no-go devices.
Thanks
Rusty