I am using CY7C65632 USB hub. Upstream is connected to WinXP PC, downstream is connected to the USB D+/D- of a MCU, which is program to be a mass storage device. Sometime when powered up, it will fail Device Manager Code 10 "Device cannot start", under the Generic USB Mass Storage Device; sometimes the enumeration is successful and a new disk drive appears in Device Manager. Why is this so? Do I need a driver for the USB hub? Thank you.