For whatever reason, the base piCore images do not enable FIQ accellerations withing dwg_otc. Which is fine if you don't have USB devices connected. Without FIQ handling, its common to see lost/corrupted USB data. I'm far from a USB expert, but I would start with
Adding
dwc_otg.fiq_fsm_mask=0xF
to your cmdline.txt file on your boot drive. There is of coarse different options for FIQ, but this enables all of the accelerations.
Other If that doesn't work, there might be other options.