Thanks for pointing out the power limmits - I should have checked them myself before posting.
I assume that the User Guide figures apply to each individual USB port and not to all four of them together.
As you suggested, the CD-Rom Drive at 1.600mA could never have worked.
The keyboard and wired mouse, (I cannot find the power rating for the Nano receiver of the Logitech Pebble wireless mouse), are both 100mA, which implies that they should work. Is there anything else I should check before sending the Neo C-UHSI back to Minix Direct, because it does not meet the published specification?