Symptoms
Have the Lenovo L220x 22" monitor. None of the usb ports seem to work - any device, including flash drives, plugged into the monitor isb ports are not recognized. The devices work when plugged into the CPU ports. OS is Vista.
Diagnosis
No USB A:B cable installed to connect computer to the hub of the display.
Solution
Connect the A:B cable from the display (the one next to the VGA connector) to your computer and your hub will work.