The circuit board on these cases are not USB 2.0 capable. They're just USB 2.0 compatible (meaning a 2.0 device will work, but only at 1.1 speeds).
I have the Antec version of these cases. I contacted Antec about it and they sent me a new circuit board straight away. Haven't had a chance to install it yet (it's for a new PC I'll be building), but this is what I discovered by googling usenet for info about the front panel USB ports.
(As a side note, no experience with Chenming customer service, but for anyone getting one of these clones, I would recommend getting the Antec brand if the price difference is negligible. I've contacted them on three separate occassions for things, and each time they responded quickly and with no questions asked. Simply put, their customer service is awesome.)