So I found out that there are apparently several types of Belkin F5U002 adapters out there. I just bought some that don't work, so watch out. They have a different usb vendor id, and they do not have a separate USB cable. Otherwise they look very similar.
They might even use the same chip, but they put out different voltages and behave a little differently.
Until I can find the correct cables, or figure these out, I am going to have to temporarily suspend the group buy.
I will keep everyone updated here.