HP LJ1200 connected to USB here:
LIBUSB: unable to query number of USB devices - rc= 1b58
Well, Sony Vaio: Everything connected to USB that should work also works (printer, all three mouses, CD drive, USB sticks) but usbres complains "no USB driver found". usbcfg works, 6 UHCI, 2 EHCI, 1 mass storage, 1 printer. The printer is connected to LPT1 redirected to USB and it was on line while testing. Also, I made sure that it really works by printing some nonsense. RC6a.